#!/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 eachNum, 'is prime'

for eachNum in range(10, 21):
    showMaxFactor(eachNum)