package main

import "fmt"

func abs(a int) int {
	if a >= 0 {
		return a
	}
	return -a
}

func main() {
	var t int
	fmt.Scan(&t)
	x := make([]int, t)
	for i := range x {
		fmt.Scan(&x[i])
	}
	prev := 0
	for i := 0; i < len(x); i++ {
		if abs(x[i]-prev) != 1 {
			fmt.Println("F")
			return
		}
		prev = x[i]
	}
	fmt.Println("T")
}