T = int(input().strip()) X = [int(input()) for _ in range(T)] if abs(X[0]) != 1: print('F') exit(0) elif T == 1: print('T') exit(0) lst = list(set([abs(a - b) for a, b in zip(X, X[1:])])) if len(lst) == 1 and lst[0] == 1: print('T') else: print('F')