bcdef
abbbc
 z
y
 reddit
abcdef
 abc
aaa
 y
z
 cbxz
aaaa

bccdb
 z
 dfdeed
 aab
 y
 abac

#include <bits/stdc++.h>
using namespace std;
int main() {
  string arr1, arr2;
  cin >> arr1 >> arr2;
  sort(arr1.begin(), arr1.end());
  sort(arr2.begin(), arr2.end(), greater<char>());
  string hi = "";
  for (int i = 0; i < arr1.size(); i++) {
    if (i % 2 == 0)
      hi += arr1[i / 2];
    else
      hi += arr2[i / 2];
  }
  cout << hi;
  return 0;
}
