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 s1, s2;
  cin >> s1 >> s2;
  int n = s2.length(), k = 0, j = n - 1;
  char name[n];
  sort(s1.begin(), s1.end());
  sort(s2.begin(), s2.end());
  for (int i = 0; i < n; i++) {
    if (s1[0] > s2[n - 1]) {
      if (i % 2 == 0)
        cout << s2[j--];
      else
        cout << s1[k++];
    } else {
      if (i % 2 == 0)
        cout << s1[k++];
      else if (i % 2 != 0)
        cout << s2[j--];
    }
  }
  return 0;
}
