func main()
	var t: int :: cui@inputInt()
	var prev: int :: 0
	for(1, t)
		var x: int :: cui@inputInt()
		if((x - prev).abs() <> 1)
			do cui@print("F\n")
			ret
		end if
		do prev :: x
	end for
	
	do cui@print("T\n")
end func