#include <iostream>

int main(void){
    int N = 0;
    int X[100] = { 0 };
    int C = 0;
    
    std::cin >> N;
    
    for (int i = 0; i < N; i++) {
        std::cin >> X[i];
        if ((C + 1 != X[i]) && (C - 1 != X[i])) {
            std::cout << "F" << std::endl;
            return 0;
        }
        C = X[i];
    }
    
    std::cout << "T" << std::endl;
    return 0;
}