N=int(input())
X = [int(input()) for i in range(N)]

X.insert(0,0)

flag=True
for i in range(N):
    if X[i]==X[i+1] or abs(X[i]-X[i+1])!=1:
        flag=False
        break
    else:
        continue

if flag:
    print('T')
else:
    print('F')