Java 代码

import java.util.Scanner;
import java.util.StringTokenizer;

public class Main
{
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);

        while (cin.hasNextLine())
        {
            StringTokenizer tokens = new StringTokenizer(cin.nextLine());
            String s = tokens.nextToken();
            String sub = tokens.nextToken();

            int p = 0;
            for (int i = 0; i <s.length(); i ++)
            {
                if (s.charAt(i) > s.charAt(p))
                    p = i;
            }

            System.out.println (s.substring(0, p+1) + sub + s.substring(p+1));
        }
    }
}