#include <bits/stdc++.h>
#include "bits/stdc++.h"
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
#include <stack>
#include <queue>
#include <cctype>
#include <stdio.h>
#include <map>
#include <unordered_map>
#include <string.h>
#include <utility>

typedef long long ll;
const int INF = 1e8;

#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
using namespace std;

typedef pair<int, int> P;

int main() {

	int T = 0;
	cin >> T;

	int st = 0;
	cin >> st;

	if (st != 1 && st != -1) {
		cout << "F" << endl;
		return 0;
	}

	int next = 0;
	for (int i = 1; i < T; i++) {
		cin >> next;

		if (abs(st - next) != 1) {
			cout << "F" << endl;
			return 0;
		}

		st = next;
	}
	cout << "T" << endl;

	return 0;
}