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());
  int index1 = 0, index2 = b.size() - 1;
  for (int i = 0; i < a.size(); i++) {
    if (i % 2 == 0) {
      cout << a[index1++];
    } else
      cout << b[index2--];
  }
}
