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;
  sort(s1.begin(), s1.end());
  sort(s2.begin(), s2.end(), greater<char>());
  string res;
  int len = s1.length();
  bool flag = true;
  int k = 0, l = 0;
  for (int i = 0; i < len; i++, flag = !flag) {
    if (flag) {
      res += (s1[k++]);
      s1.erase(s1.begin(), s1.begin() + 1);
    } else {
      res += (s2[l++]);
      s2.erase(s2.begin(), s2.begin() + 1);
    }
  }
  cout << res << endl;
}
