#coding:utf-8

old=raw_input().split('.')
new=raw_input().split('.')

if new[0] < old[0]:
	print 'YES'
	
if new[0] == old[0]:
	if new[1] < old[1]:
		print 'YES'
	elif new[1] == old[1]:
		if new[2] <= old[2]:
			print 'YES'
		else:
			print 'NO'
	else:
		print 'NO'
		
if old[0] < new[0]:
	print 'NO'