while~0: s,t=raw_input().split() while s[1:]: \x09if s[:1]==t[:1]:s,t=s[1:],t[1:] \x09else:s=`(int(s[0])+int(s[1]))%10`+s[2:] print('YNEOS')[s!=t>''or'0'<s!=t::2]
Note that non-ascii characters in the above source code will be escaped (such as \x9f).