# -*- coding: utf-8 -*-

ao,bo,co = input().split('.')
an,bn,cn = input().split('.')

yes = 'YES'
no = 'NO'

if an > ao:
    print(no)
elif an < ao:
    print(yes)
else:
    if bn > bo:
        print(no)
    elif bn < bo:
        print(yes)
    else:
        if cn > co:
            print(no)
        else:
            print(yes)