... ~~~~~

include<bits/stdc++.h>

using namespace std;

/* ###################################################################### ####################### THE BIG INT ########################## */

const int base = 1000000000; const int base_digits = 9;

struct Int {

vector<int> a;
int sign;

/*<arpa>*/

int size(){
    if(a.empty()) return 0;
    int ans=(a.size()-1)*base_digits;
    int ca=a.back();
    while(ca)
        ans++,ca/=10;
    return ans;
}

Int operator ^(const Int &v){
    Int ans=1,a=*this,b=v;
    while(!b.isZero()){
        if(b%2)
        ans*=a;
        a*=a,b/=2;
    }
    return ans;
}

string to_string(){
    stringstream ss;
    ss << *this;
    string s;
    ss >> s;
    return s;
}

int sumof(){
    string s = to_string();
    int ans = 0;
    for(auto c : s)  ans += c - '0';
    return ans;
}

/*</arpa>*/

Int() :
sign(1) {
}

Int(long long v) {
    *this = v;
}

Int(const string &s) {
    read(s);
}

void operator=(const Int &v) {
    sign = v.sign;
    a = v.a;
}

void operator=(long long v) {
    sign = 1;
    a.clear();
    if (v < 0)
        sign = -1, v = -v;
    for (; v > 0; v = v / base)
        a.push_back(v % base);
}

Int operator+(const Int &v) const {
    if (sign == v.sign) {
        Int res = v;
        for (int i = 0, carry = 0; i < (int) max(a.size(), v.a.size()) || carry; ++i) {
            if (i == (int) res.a.size())
                res.a.push_back(0);
            res.a[i] += carry + (i < (int) a.size() ? a[i] : 0);
            carry = res.a[i] >= base;
            if (carry)
                res.a[i] -= base;
        }
        return res;
    }
    return *this - (-v);
}

Int operator-(const Int &v) const {
    if (sign == v.sign) {
        if (abs() >= v.abs()) {
            Int res = *this;
            for (int i = 0, carry = 0; i < (int) v.a.size() || carry; ++i) {
                res.a[i] -= carry + (i < (int) v.a.size() ? v.a[i] : 0);
                carry = res.a[i] < 0;
                if (carry)
                res.a[i] += base;
            }
            res.trim();
            return res;
        }
        return -(v - *this);
    }
    return *this + (-v);
}

void operator*=(int v) {
    if (v < 0)
        sign = -sign, v = -v;
    for (int i = 0, carry = 0; i < (int) a.size() || carry; ++i) {
        if (i == (int) a.size())
            a.push_back(0);
        long long cur = a[i] * (long long) v + carry;
        carry = (int) (cur / base);
        a[i] = (int) (cur % base);
        //asm("divl %%ecx" : "=a"(carry), "=d"(a[i]) : "A"(cur), "c"(base));
    }
    trim();
}

Int operator*(int v) const {
    Int res = *this;
    res *= v;
    return res;
}

void operator*=(long long v) {
    if (v < 0)
        sign = -sign, v = -v;
    for (int i = 0, carry = 0; i < (int) a.size() || carry; ++i) {
        if (i == (int) a.size())
            a.push_back(0);
        long long cur = a[i] * (long long) v + carry;
        carry = (int) (cur / base);
        a[i] = (int) (cur % base);
        //asm("divl %%ecx" : "=a"(carry), "=d"(a[i]) : "A"(cur), "c"(base));
    }
    trim();
}

Int operator*(long long v) const {
    Int res = *this;
    res *= v;
    return res;
}

friend pair<Int, Int> divmod(const Int &a1, const Int &b1) {
    int norm = base / (b1.a.back() + 1);
    Int a = a1.abs() * norm;
    Int b = b1.abs() * norm;
    Int q, r;
    q.a.resize(a.a.size());

    for (int i = a.a.size() - 1; i >= 0; i--) {
        r *= base;
        r += a.a[i];
        int s1 = r.a.size() <= b.a.size() ? 0 : r.a[b.a.size()];
        int s2 = r.a.size() <= b.a.size() - 1 ? 0 : r.a[b.a.size() - 1];
        int d = ((long long) base * s1 + s2) / b.a.back();
        r -= b * d;
        while (r < 0)
            r += b, --d;
        q.a[i] = d;
    }

    q.sign = a1.sign * b1.sign;
    r.sign = a1.sign;
    q.trim();
    r.trim();
    return make_pair(q, r / norm);
}

Int operator/(const Int &v) const {
    return divmod(*this, v).first;
}

Int operator%(const Int &v) const {
    return divmod(*this, v).second;
}

void operator/=(int v) {
    if (v < 0)
        sign = -sign, v = -v;
    for (int i = (int) a.size() - 1, rem = 0; i >= 0; --i) {
        long long cur = a[i] + rem * (long long) base;
        a[i] = (int) (cur / v);
        rem = (int) (cur % v);
    }
    trim();
}

Int operator/(int v) const {
    Int res = *this;
    res /= v;
    return res;
}

int operator%(int v) const {
    if (v < 0)
        v = -v;
    int m = 0;
    for (int i = a.size() - 1; i >= 0; --i)
        m = (a[i] + m * (long long) base) % v;
    return m * sign;
}

void operator+=(const Int &v) {
    *this = *this + v;
}

void operator-=(const Int &v) {
    *this = *this - v;
}

void operator*=(const Int &v) {
    *this = *this * v;
}

void operator/=(const Int &v) {
    *this = *this / v;
}

Int operator ++(){
    *this += 1;
    return *this;
}

Int operator ++(int){
    Int temp = *this;
    *this += 1;
    return temp;
}

Int operator --(){
    *this -= 1;
    return *this;
}

Int operator --(int){
    Int temp = *this;
    *this -= 1;
    return temp;
}

bool operator<(const Int &v) const {
    if (sign != v.sign)
        return sign < v.sign;
    if (a.size() != v.a.size())
       return a.size() * sign < v.a.size() * v.sign;
    for (int i = a.size() - 1; i >= 0; i--)
        if (a[i] != v.a[i])
            return a[i] * sign < v.a[i] * sign;
    return false;
}

bool operator>(const Int &v) const {
    return v < *this;
}

bool operator<=(const Int &v) const {
    return !(v < *this);
}

bool operator>=(const Int &v) const {
    return !(*this < v);
}

bool operator==(const Int &v) const {
    return !(*this < v) && !(v < *this);
}

bool operator!=(const Int &v) const {
    return *this < v || v < *this;
}

void trim() {
    while (!a.empty() && !a.back())
        a.pop_back();
    if (a.empty())
        sign = 1;
}

bool isZero() const {
    return a.empty() || (a.size() == 1 && !a[0]);
}

Int operator-() const {
    Int res = *this;
    res.sign = -sign;
    return res;
}

Int abs() const {
    Int res = *this;
    res.sign *= res.sign;
    return res;
}

long long longValue() const {
    long long res = 0;
    for (int i = a.size() - 1; i >= 0; i--)
        res = res * base + a[i];
    return res * sign;
}

friend Int gcd(const Int &a, const Int &b) {
    return b.isZero() ? a : gcd(b, a % b);
}

friend Int lcm(const Int &a, const Int &b) {
    return a / gcd(a, b) * b;
}

void read(const string &s) {
    sign = 1;
    a.clear();
    int pos = 0;
    while (pos < (int) s.size() and (s[pos] == '-' || s[pos] == '+')) {
        if (s[pos] == '-')
            sign = -sign;
        ++pos;
    }

    for (int i = s.size() - 1; i >= pos; i -= base_digits) {
        int x = 0;
        for (int j = max(pos, i - base_digits + 1); j <= i; j++)
            x = x * 10 + s[j] - '0';
        a.push_back(x);
    }
    trim();
}

friend istream& operator>>(istream &stream, Int &v) {
    string s;
    stream >> s;
    v.read(s);
    return stream;
}

friend ostream& operator<<(ostream &stream, const Int &v) {
    if (v.sign == -1)
       stream << '-';
    stream << (v.a.empty() ? 0 : v.a.back());
    for (int i = (int) v.a.size() - 2; i >= 0; --i)
        stream << setw(base_digits) << setfill('0') << v.a[i];
    return stream;
}

static vector<int> convert_base(const vector<int> &a, int old_digits, int new_digits) {
    vector<long long> p(max(old_digits, new_digits) + 1);
    p[0] = 1;
    for (int i = 1; i < (int) p.size(); i++)
        p[i] = p[i - 1] * 10;
    vector<int> res;
    long long cur = 0;
    int cur_digits = 0;
    for (int i = 0; i < (int) a.size(); i++) {
        cur += a[i] * p[cur_digits];
        cur_digits += old_digits;
        while (cur_digits >= new_digits) {
            res.push_back(int(cur % p[new_digits]));
            cur /= p[new_digits];
            cur_digits -= new_digits;
        }
    }
    res.push_back((int) cur);
    while (!res.empty() && !res.back())
        res.pop_back();
    return res;
}

typedef vector<long long> vll;

static vll karatsubaMultiply(const vll &a, const vll &b) {
    int n = a.size();
    vll res(n + n);
    if (n <= 32) {
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                res[i + j] += a[i] * b[j];
        return res;
    }

    int k = n >> 1;
    vll a1(a.begin(), a.begin() + k);
    vll a2(a.begin() + k, a.end());
    vll b1(b.begin(), b.begin() + k);
    vll b2(b.begin() + k, b.end());

    vll a1b1 = karatsubaMultiply(a1, b1);
    vll a2b2 = karatsubaMultiply(a2, b2);

    for (int i = 0; i < k; i++)
        a2[i] += a1[i];
    for (int i = 0; i < k; i++)
        b2[i] += b1[i];

    vll r = karatsubaMultiply(a2, b2);

    for (int i = 0; i < (int) a1b1.size(); i++)
        r[i] -= a1b1[i];
    for (int i = 0; i < (int) a2b2.size(); i++)
        r[i] -= a2b2[i];

    for (int i = 0; i < (int) r.size(); i++)
        res[i + k] += r[i];
    for (int i = 0; i < (int) a1b1.size(); i++)
        res[i] += a1b1[i];
    for (int i = 0; i < (int) a2b2.size(); i++)
        res[i + n] += a2b2[i];
    return res;
}

Int operator*(const Int &v) const {
    vector<int> a6 = convert_base(this->a, base_digits, 6);
    vector<int> b6 = convert_base(v.a, base_digits, 6);

    vll a(a6.begin(), a6.end());
    vll b(b6.begin(), b6.end());

    while (a.size() < b.size())
        a.push_back(0);
    while (b.size() < a.size())
        b.push_back(0);
    while (a.size() & (a.size() - 1))
        a.push_back(0), b.push_back(0);

    vll c = karatsubaMultiply(a, b);
    Int res;
    res.sign = sign * v.sign;
    for (int i = 0, carry = 0; i < (int) c.size(); i++) {
        long long cur = c[i] + carry;
        res.a.push_back((int) (cur % 1000000));
        carry = (int) (cur / 1000000);
    }
    res.a = convert_base(res.a, 6, base_digits);
    res.trim();
    return res;
}

//Added part.

friend Int max(const Int &a,const Int &b){
    if(a<b){
        return a;
    }
    return b;
}

friend Int max(const Int &a,const int32_t &B){
    Int b = B;
    return max(a,b);
}

friend Int max(const Int &a,const int64_t &B){
    Int b = B;
    return max(a,b);
}

friend Int min(const Int &a,const Int &b){
    if(a>b){
        return b;
    }
    return a;
}

friend Int min(const Int &a,const int32_t &B){
    Int b = B;
    return min(a,b);
}

friend Int min(const Int &a,const int64_t &B){
    Int b = B;
    return min(a,b);
}

friend Int pow(const Int &a,const Int &b){
    Int _c = 1;
    Int _b = b;
    Int _a = a;
    while(_b != 0){
        if(_b%2){
           _c *= _a;
       }
       _a *= _a;
       _b /= 2;
    }
    return _c;
}

friend Int pow(const Int &a,const int32_t &B){
    Int b = B;
    return pow(a,b);
}

friend Int pow(const Int &a,const int64_t &B){
    Int b = B;
    return pow(a,b);
}

friend Int sqrt(Int a) {
    Int x0 = a, x1 = (a+1)/2;
    while (x1 < x0) {
        x0 = x1;
        x1 = (x1+a/x1)/2;
    }
    return x0;
}

}; /* ####################### THE BIG INT ########################## ###################################################################### */

int main(){

ios_base :: sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

long long n;cin>>n;
Int ans=1;
bool flag=true,flag1=true;
while(n--)
{
    Int a;
    cin>>a;
    if(a==0)flag1=false;
    if(ans.size()>19)
    {
       flag=false;
    }
    if(flag)ans*=a;
}

if(!flag1)
{
    cout<<0<<endl;return 0;
}
if(!flag or ans.size()>19)cout<<-1<<endl;
else if(ans.size()==19)
{
    string s=ans.to_string();
    if(s[0]=='1')
    {
       for(int i=1;i<19;++i)
       {
         if(s[i]!='0')
         {
          cout<<-1<<endl;exit(0);
         }
       }
       cout<<ans<<endl;
    }
    else
    {
       cout<<-1<<endl;
    }
}
else cout<<ans<<endl;

} ~~~~~