#include <iostream>
#include <vector>
#include <algorithm>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(s) cerr << __LINE__ << "\t:" << #s << " = " << (s) << endl
    
using namespace std;

int main () {
    int T;
    cin >> T;
    int x = 0;
    REP (i, 0, T) {
	int xi;
	cin >> xi;
	if (abs(x - xi) != 1) {
	    cout << 'F' << endl;
	    return 0;
	}
	x = xi;
    }
    cout << "T" << endl;
    
    return 0; 
}