#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main() {
  int t;
  cin >> t;
  vector<int> a(t);
  rep(i, t) cin >> a[i];
  int now = 0;
  rep(i, t) {
    if (abs(now - a[i]) != 1) {
      cout << "F" << endl;
      return 0;
    }
    now = a[i];
  }
  cout << "T" << endl;
  return 0;
}