#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int A[200];

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int N;
    std::cin >> N;

    for(int i=1;i<=N;++i){
        std::cin >> A[i];
    }
    
    for(int i=0;i+1<=N;++i){
        if(abs(A[i] - A[i+1]) != 1){
            std::cout << "F" << std::endl;
            return 0;
        }
    }

    std::cout << "T" << std::endl;
}