import java.util.Scanner;
public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        String strval = sc.nextLine();
        char fc=sc.next().charAt(0);
        char sch=sc.next().charAt(0);
        String result = "";
         if (fc.length() != 1 || sch.length() != 1) {
            System.out.println("Invalid input");
            return;
        }
        for (int i=0;i<strval.length();i++){
            char ch =strval.charAt(i);
            if(ch==fc){
                result+=sch;
            }else{
                result+=ch;
            }
        }
        System.out.println(result);
    }
}