namespace number_theory { ll gcd(ll x, ll y) { if (x == 0) return y; if (y == 0) return x; return gcd(y, x % y); } bool isprime(ll n) { if (n <= 1) return false; if (n <= 3) return true;
if (n % 2 == 0 || n % 3 == 0) return false;
for (ll i = 5; i * i <= n; i += 6)
if (n % i == 0 || n % (i+2) == 0)
return false;
return true;
}
bool prime[15000105];
void sieve(int n) {
for (ll i = 0; i <= n; i++) prime[i] = 1;
for (ll p = 2; p * p <= n; p++) {
if (prime[p] == true) {
for (ll i = p * p; i <= n; i += p)
prime[i] = false;
}
}
prime[1] = prime[0] = 0;
}
vector<ll> primelist;
bool __primes_generated__ = 0;
void genprimes(int n) {
__primes_generated__ = 1;
sieve(n + 1);
for (ll i = 2; i <= n; i++) if (prime[i]) primelist.push_back(i);
}
vector<ll> factors(ll n) {
if (!__primes_generated__) {
cerr << "Call genprimes you dope" << endl;
exit(1);
}
vector<ll> facs;
for (ll i = 0; primelist[i] * primelist[i] <= n && i < primelist.size(); i++) {
if (n % primelist[i] == 0) {
while (n % primelist[i] == 0) {
n /= primelist[i];
facs.push_back(primelist[i]);
}
}
}
if (n > 1) {
facs.push_back(n);
}
sort(facs.begin(), facs.end());
return facs;
}
vector<ll> getdivs(ll n) {
vector<ll> divs;
for (ll i = 1; i * i <= n; i++) {
if (n % i == 0) {
divs.push_back(i);
divs.push_back(n / i);
}
}
getunique(divs);
return divs;
} }








