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

bccdb
 z
 dfdeed
 aab
 y
 abac

import java.util.*;

/**
 * Created by vrajegowda on 6/6/17.
 */
public class NamingComapany {
    public static void main(String[] args){
        String oleg;
        String igor;
        Scanner sc = new Scanner(System.in);
        oleg= sc.next();
        igor=sc.next();
        char [] arr1=oleg.toCharArray();
        char [] arr2=igor.toCharArray();
        Arrays.sort(arr1);
        Arrays.sort(arr2);

        String res="";
        int k=0;
        boolean f=false;
        int i=0;
        int j=arr2.length-1;
        while(k<arr1.length){
            k++;
            if(!f) {
                res +=arr1[i];
                i++;
                f=true;
            }
            else{
                res+=(arr2[j]);
                j--;
                f=false;
            }

        }
        System.out.println(res);
    }
}
