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

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);  
	int t;
	cin >> t;
	int x = 0;
	while(t--) {
		int a;
		cin >> a;
		if(abs(x - a) != 1) {
			cout << "F" << endl;
			return 0;
		}
		x = a;
	}
	cout << "T" << endl;
	return 0;	
}