#!/usr/bin/env python
def showMaxFactor(num):
count = num / 2
while count > 1:
if num % count == 0:
print 'largest factor of %d is %d' % (num, count)
break
count -= 1
else:
print num, "is prime"
for eachNum in range(10, 21):
showMaxFactor(eachNum)