#include<iostream>
#include<iomanip>
#include<math.h>
#include<vector>
#include<algorithm>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<string>
#include<bitset>
#include<random>
#define INF 1000000000ll
#define MOD 1000000007ll
#define EPS 1e-10
#define REP(i,m) for(long long i=0; i<m; i++)
#define FOR(i,n,m) for(long long i=n; i<m; i++)
#define DUMP(a) for(long long dump=0; dump<(ll)a.size(); dump++) { cout<<a[dump]; if(dump!=(ll)a.size()-1) cout<<" "; else cout<<endl; }
#define ALL(v) v.begin(),v.end()
#define pb push_back
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
typedef long double ld;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	ll t;
	cin>>t;
	vector<ll> n(t);
	REP(i,t) cin>>n[i];
	if(n[0]!=0) {
		cout<<"F"<<endl;
		return 0;
	}
	REP(i,t-1) {
		if(abs(n[i]-n[i+1])!=1) {
			cout<<"F"<<endl;
			return 0;
		}
	}
	cout<<"T"<<endl;
	return 0;
}