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 x, y;
  cin >> x >> y;
  sort(x.begin(), x.end());
  sort(y.begin(), y.end(), greater<int>());
  for (long long int i = (0); i < (long long int)(x.length()); ++i) {
    if (i & 1) {
      cout << y[i / 2];
    } else {
      cout << x[i / 2];
    }
  }
  cout << endl;
  return 0;
}
