import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int t = sc.nextInt();
    int[] x = new int[t];
    for(int i = 0; i < t; i++) {
      x[i] = sc.nextInt();
    }
    String ans = "T";
    if((x[0] != 1) && (x[0] != -1)) ans = "F";
    for(int i = 1; i < t; i++) {
      if(Math.abs(x[i] - x[i - 1]) != 1) ans = "F";
    }
    System.out.println(ans);
  }
}