#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;

int main()
{
	int n; cin >> n;
	int p = 0;

	bool flag = true;
	for (int i = 0; i < n; i++) {
		int x; cin >> x;
		if (abs(x - p) != 1)flag = false;
		p = x;
	}

	cout << (flag ? "T" : "F") << endl;

    return 0;
}