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

#define vi vector<int>
#define PB push_back
#define vll vector<long long>
#define ll long long
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define ld long double
#define vld vector<long double>

const ll mod = 998244353;
const ll MOD = 1e9 + 7;

void solve(int tst){
    
    int n;
    string s, t;
    cin >> n;
    cin >> s >> t;
    if (s == t){
        cout << "YES\n";
        return;
    }

    if (n == 1 && s != t){
        cout << "NO\n";
        return;
    }

    for (int i = n - 2; i >= 0; i--){
        if (t[i] != t[i + 1]){
            cout << "YES\n";
            return;
        }
        if (s[i + 1] != t[i + 1]){
            cout << "NO\n";
            return;
        }
    }

}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    // pre();
    int tc = 1;
    cin >> tc;
    for (int i = 1; i <= tc; i++){
        solve(i);
    }
    return 0;
}