/**
 * Created by IntelliJ IDEA.
 * User: me
 * Date: 12.09.2006
 * Time: 17:17:15
 * To change this template use File | Settings | File Templates.
 */
import java.io.*;
public class TranslateByte {
    public static void main(String[] args)
        throws IOException
    {
        byte from = (byte)args[0].charAt(0);
        byte to   = (byte)args[1].charAt(0);
 
        int b;
        while ((b = System.in.read()) != -1) {
            System.out.write(b == from ? to : b);
        }
    }
}