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

#define INF 1.1e9
#define LINF 1.1e18
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define BIT(x,n) bitset<n>(x)
#define PI 3.14159265358979323846

typedef long long ll;
typedef pair<ll,ll> P;
typedef pair<int,P> PP;

//-----------------------------------------------------------------------------


int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int t,x[100];
	cin>>t;
	REP(i,t) cin>>x[i];
	if(x[0]!=-1&&x[0]!=1) {
		cout<<"F"<<endl;
		return 0;
	}
	REP(i,t-1) {
		if(abs(x[i]-x[i+1])!=1) {
			cout<<"F"<<endl;
			return 0;
		}
	}
	cout<<"T"<<endl;

	return 0;
}