t = int(input())
x = [int(input()) for _ in range(t)]

if x[0] not in (1, -1):
    print("F")
else:
    valid = True
    for i in range(t - 1):
        if abs(x[i+1] - x[i]) != 1:
            valid = False
            break
    print("T" if valid else "F")