#coding:utf-8

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

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