#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
int T, x;
bool flag = true;
vector<int> v;
int main(){
    cin >> T;
    for(int i=0; i<T; ++i){
        cin >> x;
        v.push_back(x);
    }
    if(T <= 1){
        if(v[0] == 0 || (v[0] != -1 && v[0] != 1)) flag = false;
    }
    for(int i=1; i<T; ++i){
        if(v[0] == 0 || (v[i] - v[i-1] != 1 && v[i] - v[i-1] != -1)) {
            flag = false;
            break;
        }
    }
    if(flag){
        cout <<"T" << endl;
    }else{
        cout << "F" << endl;
    }
    return 0;
}