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

if x[0] == 1 or x[0] == -1:
    for i in range(n-1):
        if abs(x[i+1] - x[i]) != 1:
            print('F')
            break
    else:
        print('T')
else:
    print('F')