You are given an integer $*a*$ that consists of $*n*$ digits. You are also given a sequence of digits $*s*$ of length $*m*$. The digit in position $*j*$ ($1 ≤ *j* ≤ *m*$) of sequence $*s*$ means that you can choose an arbitrary position $*i*$ ($1 ≤ *i* ≤ *n*$) in $*a*$ and replace the digit in the chosen position $*i*$ with $*s*_{*j*}$. Each element in the sequence $*s*$ can participate in no more than one replacing operation.

Your task is to perform such sequence of replacements, that the given number $*a*$ gets maximum value. You are allowed to use not all elements from $*s*$.

Input

The first line contains positive integer $*a*$. Its length $*n*$ is positive and doesn't exceed $10^{5}$. The second line contains sequence of digits $*s*$. Its length $*m*$ is positive and doesn't exceed $10^{5}$. The digits in the sequence $*s*$ are written consecutively without any separators.

The given number $*a*$ doesn't contain leading zeroes.

Output

Print the maximum value that can be obtained from $*a*$ after a series of replacements. You are allowed to use not all elements from $*s*$. The printed number shouldn't contain any leading zeroes.