T = int(input())
i = 0
j = 0
a = [0]
c = "t"
for i in range(T):
    a.append(int(input()))

for j in range(T):    
    s = int(a[j]) - int(a[j + 1])
    A = abs(s)
    if A != 1:
        c = "f"

if c == "t":
    print("T")
else:
    print("F")