ABC.cpp

#include<bits/stdc++.h>
using namespace std;
  
int main()
{
    int n;
    cin>>n;
    for(int i=0;i<n;i++)
    {
        int a;
        cin>>a;
        string s;
        cin>>s;
        if(a==2)
        {
            if(s[0]==s[1])
            {
                cout<<"NO"<<endl;
            }
            else
            {
                cout<<"YES"<<endl;
            }
        }
        else if(a>2)
        {
            cout<<"NO"<<endl;
        }
        else
        {
            cout<<"YES"<<endl;
        }
    }
    return 0;
}