/* -*- coding: utf-8 -*-
 *
 * 627.cc: No.627 ランダムウォークの軌跡 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  int px = 0;
  for (int i = 0; i < n; i++) {
    int xi;
    scanf("%d", &xi);

    if (abs(px - xi) != 1) {
      puts("F");
      return 0;
    }

    px = xi;
  }

  puts("T");
  return 0;
}