#include <bits/stdc++.h>
using namespace std;

int main()
{
int i;
int T;
int X;
int iChk;

	cin >> T;

	iChk = 0;
	for( i = 0; i < T; i++ )
	{
		cin >> X;

		iChk -= X;
		iChk *= iChk;
		if( iChk != 1 ) break;

		iChk = X;
	}

	if( i == T )
		cout << "T" << endl;
	else
		cout << "F" << endl;

	return 0;
}