CF670F Restore a Number

Vasya decided to pass a very large integer $ n $ to Kate. First, he wrote that number as a string, then he appended to the right integer $ k $ — the number of digits in $ n $ . Magically, all the numbers were shuffled in arbitrary order while this note was passed to Kate. The only thing that Vasya remembers, is a non-empty substring of $ n $ (a substring of $ n $ is a sequence of consecutive digits of the number $ n $ ). Vasya knows that there may be more than one way to restore the number $ n $ . Your task is to find the smallest possible initial integer $ n $ . Note that decimal representation of number $ n $ contained no leading zeroes, except the case the integer $ n $ was equal to zero itself (in this case a single digit 0 was used).

The first line of the input contains the string received by Kate. The number of digits in this string does not exceed $ 1000000 $ . The second line contains the substring of $ n $ which Vasya remembers. This string can contain leading zeroes. It is guaranteed that the input data is correct, and the answer always exists.

Print the smalles integer $ n $ which Vasya could pass to Kate.