#include<bits/stdc++.h>
using namespace std;
int main(){
    int t;
    cin>>t;
    vector<int> x(t+1),diff(t);
    x.front()=0;
    for(int i=1;i<=t;++i){
        cin>>x[i];
        diff[i-1]=abs(x[i]-x[i-1]);
    }
    diff.erase(unique(diff.begin(),diff.end()),diff.end());
    puts(diff.size()==1&&diff.front()==1?"T":"F");
}