#include <iostream>
#include <string>
#include <stdio.h>

using namespace std;

int main() {
    int t,i,x1,x2;
    x1 = 0;
    string a = "T";
    cin >> t;
    for(i=0; i<t; i++) {
        cin >> x2;
        if(x1!=x2+1 && x1!=x2-1) {
            a = "F";
        }
        x1 = x2;
    }
    cout << a;
}