#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
#include <cmath>
using namespace std;

int main()
{
    int b;
    int n;
    int N;
    cin >> N;
    b = 0;
    for(int i = 0;i < N;i++)
    {
        cin >> n;
        if(abs(n - b) != 1)
        {
            cout << "F" << endl;
            return 0;
        }
        b = n;
    }
    cout << "T" << endl;
    return 0;

}