// editor3
import java.util.*;
public class Main{
    public static void main(String args[]){
        Scanner sc=new Scanner(System.in);
        String s=sc.nextLine();
        String a=sc.next();
        String b=sc.next();
        if(a.length!=1 || b.length!=1){
            System.out.pritnln("Invalid input");
            return;
        }
        System.out.println(s.replace(a,b));
    }
}