#include<bits/stdc++.h>
using namespace std;
int main(){
	int w, n, s1 = 0, s2 = 0;
	char c;
	cin >> n;
	if(n % 2 == 0) w = n / 2;
	else w = n / 2 + 1;
	for(int i = 1; i <= n; i++){
		cin >> c;
		if(c == 'A') s1++;
		else if(c == 'T') s2++;
		if(s1 >= w){
			cout << "A";
			return 0;
		}
		if(s2 >= w) {
			cout << "T";
			return 0;
		}
	}
	return 0;
}