#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define erep(i,a,b) for(int i=a;i<=(int)(b);++i)
#define per(i,a,b) for(int i=(a);i>(b);--i)
#define eper(i,a,b) for(int i=(a);i>=b;--i)
#define pb push_back
#define mp make_pair
#define INF 100100100100
#define MOD 1000000007
#define ALL(x) begin(x),end(x)
using namespace std;
typedef long long ll;
typedef pair<int,int> Pii;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return a/gcd(a, b)*b;}

int t;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
    cin >> t;
    int a;
    cin >> a;
    if (abs(a) != 1) {
        cout << "F" << endl;
        return 0;
    }
    rep(i, 0, t-1) {
        int in; cin >> in;
        int dist = abs(in - a);
        if (dist != 1) {
            cout << "F" << endl;
            return 0;
        }
        a = in;
    }
    cout << "T" << endl;
    return 0;
}