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;
bool comp(char a, char b) { return a > b; }
int main() {
  std::ios::sync_with_stdio(NULL);
  cin.tie(NULL);
  cout.tie(NULL);
  string s1, s2;
  cin >> s1 >> s2;
  int n = s1.length();
  sort(s1.begin(), s1.end());
  sort(s2.begin(), s2.end(), comp);
  for (int i = 0; i < n; i++) {
    if (i & 1)
      cout << s2[i / 2];
    else
      cout << s1[i / 2];
  }
  return 0;
}
