Two integers are given. Print the maximum number that can be obtained from their digits. For example, from digits of numbers $345$ and $6090737$ we can get the maximum number $9776543300$. \InputFile Two numbers $a$ and $b~(1 \le a, b \le 10^9)$ are given in one line. \OutputFile Print the biggest number that can be obtained from digits of numbers $a$ and $b$.