bcdef
abbbc
 z
y
 reddit
abcdef
 abc
aaa
 y
z
 cbxz
aaaa

bccdb
 z
 dfdeed
 aab
 y
 abac

#include <bits/stdc++.h>
char a[300002], b[300002];
int main() {
  scanf("%s%s", a, b);
  int n = strlen(a);
  std::sort(a, a + n);
  std::sort(b, b + n);
  std::reverse(b, b + n);
  for (int i = 0; i < n; i++)
    if (i & 1)
      printf("%c", b[i / 2]);
    else
      printf("%c", a[i / 2]);
  return 0;
}
