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;
string a, b;
int main() {
  cin >> a >> b;
  sort(a.begin(), a.end());
  sort(b.begin(), b.end(), greater<char>());
  for (int i = 0; i < a.size(); i++) {
    if (i & 1)
      cout << b[i / 2];
    else
      cout << a[i / 2];
  }
  cout << endl;
  return 0;
}
