#include <iostream>
#include <math.h>
#include <algorithm>
#include <functional>
#include <vector>
#include <typeinfo>
#include <climits>
#include <ctype.h>
#include <string>
#include <stdio.h>
using namespace std;
#define INIT cin.tie(0); ios::sync_with_stdio(false);
#define FOR(i, a, n) for (int i = a; i < n; i++)
#define REP(i, n) for(int i = 0; i < n; i++)

int main(){
    INIT;

    int n;
    cin >> n;
    int A[n + 1];
    A[0] = 0;
    REP(i, n) cin >> A[i + 1];

    int f = 1;
    REP(i, n){
        if(A[i] + 1 != A[i + 1] and A[i] - 1 != A[i + 1]){
            f = 0;
            break;
        }
    }
    if(f == 1) cout << 'T' << endl;
    else cout << 'F' << endl;

    return 0;
}