#include <bits/stdc++.h>
#define ll long long
using namespace std;

bool isPrime(int num) {
    if (num <= 1) {
        return false;
    }
    for (int i = 2; i <= sqrt(num); ++i) {
        if (num % i == 0) {
            return false;
        }
    }
    return true;
}

ll factorial(int n) {
    if (n == 0)
        return 1;
    else
        return (n * factorial(n - 1));
}

ll ncr(ll n, ll r) {
    ll value;
    value = factorial(n) / (factorial(r) * factorial(n - r));
    return value;
}
int main()
{
    int t;
    cin >> t;
    while (t--) 
    {
        int n;
        cin>>n;
        vector <int> w;
        for(int i=0;i<n;i++)
        {
            int h;
            cin>>h;
            w.push_back(h);
        }
        if(is_sorted(w.begin(), w.end()))
        {
            cout<<"YES";
        }
        else
        {
            vector <int> p;
            vector <int> q;
            for (int i = 0; i < n-1; i++) 
            {
                if (w[i] >= 10) 
                {
                    int h = w[i] / 10;
                    int g = w[i] % 10;
                    q.push_back(h);
                    q.push_back(g);
                }
                else
                {
                    q.push_back(w[i]);
                }
            }
            q.push_back(w[n-1]);
            if(is_sorted(q.begin(), q.end()))
                {
                    cout<<"YES";
                    //s=1;
                }
            else
            {
                int g=0;
                for(int i=0;i<n-1;i++)
                {
                    if(w[i]>w[i+1] && w[i]/10==0)
                    {
                        cout<<"NO";
                        g=1;
                        break;
                    }
                    else if(w[i]>w[i+1]&& w[i]>=10)
                    {
                        int h = w[i] / 10;
                        int g = w[i] % 10;
                        p.push_back(h);
                        p.push_back(g);
                    }
                    else
                    {
                        p.push_back(w[i]);
                    }
                }
                p.push_back(w[n-1]);
                if(g!=1)
                {
                    if(is_sorted(p.begin(), p.end()))
                    {
                        cout<<"YES";
                    }
                    else
                    {
                        cout<<"NO";
                    }
                }
            }
            
        }
        cout<<endl;
    }
    return 0;
}