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

bccdb
 z
 dfdeed
 aab
 y
 abac

import java.util.Arrays;
import java.util.Scanner;

public class Naming {

	public static void main(String[] args) {
		Scanner s=new Scanner(System.in);
		String line1=s.nextLine();
		String line2=s.nextLine();
		int[] a1=new int[line1.length()];
		int[] a2=new int[line2.length()];
		for (int i=0; i<a1.length; i++) {
			a1[i]=line1.charAt(i);
			a2[i]=line2.charAt(i);
		}
		Arrays.sort(a1);
		Arrays.sort(a2);
		
		String s1=toString(a1);
		String s2=toString(a2);
		for (int i=0; i<s1.length(); i++) {
			if (i%2==0) {
				int index=i/2;
				System.out.print(s1.charAt(index));
			}
			else {
				int index=i/2;
				System.out.print(s2.charAt(s2.length()-1-index));
			}
		}
	}
	
	public static String toString(int[] st) {
		StringBuilder sb=new StringBuilder("");
		for (int i:st) {
			sb.append((char)i+"");
		}
		return sb.toString();
	}

}
