#yuki_627
import sys

t=int(raw_input())
x=[]
for i in xrange(t):
 x.append(int(raw_input()))
if x[0]==0:
 print 'F'
 sys.exit()
for i in xrange(1,t):
 if abs(x[i-1]-x[i])!=1:
  print 'F'
  sys.exit()
print 'T'