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

const int min_n = 1;
const int max_n = 30;

int main(){
    registerValidation();

    int n = inf.readInt(min_n, max_n);
    inf.readEoln();
    
    string s = inf.readString();
    assert((int)s.size() == n);
    for(auto c: s){
        assert('A' <= c && c <= 'Z');
    }

    inf.readEof();
}