#include <iostream>
#include <math.h>
#include <algorithm>
#include <functional>
#include <vector>
#include <typeinfo>
#include <climits>
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 t;
    cin >> t;
    int X[t];
    REP(i, t) cin >> X[i];

    int f = 1;
    FOR(i, 1, t){
        if(X[i - 1] + 1 == X[i] or X[i - 1] - 1 == X[i]){
            int a = 0;
        }else{
            f = 0;
            break;
        }
    }
    if(f == 0) cout << "F" << endl;
    else cout << "T" << endl;


    return 0;
}