#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>
#include <set>
#include <sstream>

using namespace std;


int main() {
	int i, j, k;   
	int t;
	vector<int>a;

	cin >> t;

	for (i = 0; i < t; i++) {
		
		int num;
		cin >> num;

		if (i == 0 && num == 0) {
			cout << "F" << endl;
			return 0;
		}

		a.push_back(num);
	}

	if (t == 1) {
		if (a[0] == 1 || a[0] == -1) {
			cout << "T" << endl;
			return 0;
		}
		else {
			cout << "F" << endl;
			return 0;
		}
	}


	for (i = 1; i < t; i++) {
		if (abs(a[i] - a[i - 1]) != 1) {
			cout << "F" << endl;
			return 0;
		}
	}

	cout << "T" << endl;

	getchar();
	getchar();
	return 0;
}