A-ABC.cpp

#include "bits/stdc++.h"
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

using namespace std;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template<class T> using pq = priority_queue<T>;
template<class T> using pqg = priority_queue<T, vector<T>, greater<T>>;

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define ins insert

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

const int MOD = 1000000007;
const char nl = '\n';
const int MX = 100001; 

void solve() {
    int n;cin>>n;
    string s;cin>>s;
    if (s.length() == 1) cout<<"YES"<<endl;
    else if (s.length() == 2) if(s[0]==s[1]) cout<<"NO"<<endl;
    						  else cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
}

int main() {
    cin.tie(0)->sync_with_stdio(0); 
    cin.exceptions(cin.failbit);
 	
    int T = 1;
    cin >> T;
    while(T--) {
        solve();
    }
 
	return 0;
}