# L-22 MCS 260 Wed 17 Oct 2007 : count words
#
# This program counts the number times
# the sequence 'the' occurs in a text.
#

def add_to_buffer(b,c):
   "adds c to a 3-letter buffer b"
   B = b
   if len(b) == 3:
      B[0] = B[1]; B[1] = B[2]; B[2] = c
   else:
      B.append(c)
   return B

search = ['t','h','e']
buffer = []
name = raw_input('give file name : ')
file = open(name,'r')
cnt = 0
while True:
   c = file.read(1)
   if c == '': break
   buffer = add_to_buffer(buffer,c)
   if buffer == search: cnt += 1
file.close()
print '#occurrences of the : %d' % cnt