#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1LL << 30;
int MOD = 1e9+7;
main(){
    int N;
    cin >> N;
    int pos = 0;
    for(int i = 0;i < N;i++){
        int a;
        cin >> a;
        if(abs(a - pos) != 1){
            cout << "F" << endl;
            return 0;
        }
        pos = a;
    }
    cout << "T" << endl;
}