#include<iostream>
 #include<stdlib.h>
 using namespace std;

 int main()
 {
    int T,x,sub_x=0;
    cin>>T;
    for(int i=0; i<T; i++){
        cin>>x;
        if(i==0){ continue;}
        else{
            if(x-sub_x!=1 || x-sub_x!=-1){
                cout<<"F"<<endl;
                return 0;
            }
            else { continue; }
        }
        sub_x = x;
    }
    cout<<"T"<<endl;
    
    return EXIT_SUCCESS;
 }