#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int t, x = 0, temp;
    cin >> t;
    for (int i = 0; i < t; i++){
        cin >> temp;
        if (abs(temp - x) != 1){
            cout << "F" << endl;
            return 0;
        }
        x = temp;
    }
    cout << "T" << endl;
}