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

int main()
{
	int T;
	cin >> T;

	string ans = "T";
	int last = 0;
	for( int i = 0; i < T; i++ ) {
		int X;
		cin >> X;
		if( abs(X - last) == 1 ) {}
		else ans = "F";
		last = X;
	}

	cout << ans << endl;
}