list = map(int, raw_input().split()) del list[0] flag = "T" if list[0] == 1 or list[0] == -1: for i in range(len(list) - 1): if list[i] + 1 == list[i + 1] or list[i] - 1 == list[i + 1]: flag = "T" else: flag = "F" print(flag) else: flag = "F" print(flag)