import sys
input = lambda: sys.stdin.readline()[:-1]
flag=1
t=int(input())
pre=int(input())
if pre!=-1 and pre!=1:flag=0
for i in range(t-1):
	now=int(input())
	if now==pre+1 or now==pre-1:
		pass
	else:
		flag=0
		break

	pre=now
print('T' if flag else 'F')