#!/usr/bin/env python

def showMaxFactor(num):
    count = num / 2
    while count > 1:
        if (num % count == 0): break
	    print 'largest factor of %d is %d' % \
		(num, count)
	    break
        count = count - 1
    else:
	print eachNum, 'is prime'

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