YES or YES?

#include <bits/stdc++.h>

using namespace std;

signed main()
{
    int t , n;
    string s;
    cin >> t;
    while(t--){
        cin >> s;
        n = s.size();
        for(int i = 0; i < n; i++){
            s[i] = tolower(s[i]);
        }
        if(s == "yes"){
            cout << "YES" << endl;
        }else{
            cout << "NO" << endl;
        }
    }
}