import java.io.PrintWriter;
import java.util.Scanner;
public class Main {
public void run(){
byte[] a, b;
Scanner in
= new Scanner
(System.
in);
a = (in.nextLine() + 'A').getBytes();
b = (in.nextLine() + 'A').getBytes();
int fullLength = a.length + b.length - 2, ai = 0, bi = 0;
for(int i = 0; i < fullLength; i++){
if(a[ai] > b[bi]) {
out.print((char) b[bi]);
bi++;
}
else if(a[ai] < b[bi]) {
out.print((char) a[ai]);
ai++;
}
else {
if(a[ai + 1] > b[bi + 1]) {
out.print((char) b[bi]);
bi++;
}
else if(a[ai + 1] < b[bi + 1]) {
out.print((char) a[ai]);
ai++;
}
else {
if(a[a.length - 2] >= b[b.length - 2]) {
out.print((char) b[bi]);
bi++;
}
else {
out.print((char) a[ai]);
ai++;
}
}
}
}
out.flush();
out.close();
}
public static void main
(String[] args
) { new Main().run();
}
}
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