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

 int main()
 {
    int T,x,sub_x=0,flag=0;
    cin>>T;
    for(int i=0; i<T; i++){
        cin>>x;
            if(x-sub_x==1 || x-sub_x==-1){
                sub_x = x;
            }
            else { cout<<'F'<<endl; return 0; }
        }
    cout<<'T'<<endl;
    return EXIT_SUCCESS;
 }