input_count = int(input())

current_place = 0
before_place = 0
answer = True

for i in range(0, input_count):
    if i == 0 and int(input()) == 0:
        answer = False
        break
    elif i == 0:
        before_place = int(input())
        continue
    else:
        current_place = int(input())

    if current_place == before_place + 1 or current_place == before_place - 1:
        answer = True
    else:
        answer = False
        break

    before_place = current_place

if answer:
    print("T")
else:
    print("F")