// editor3
import java.util.*;

class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        if(!sc.hasNextLine()){
            System.out.println("Invalid input");
            return;
        }
        String str1 =sc.nextLine();
        StringBuilder str = new StringBuilder(str1);
        
        if(!sc.hasNextLine()){
            System.out.println("Invalid input");
            return;
        }
        char r = sc.nextLine().charAt(0);
        if(!sc.hasNextLine()){
            System.out.println("Invalid input");
            return;
        }
        char c = sc.nextLine().charAt(0);
        
        System.out.println(str.replace(r,c));
        
        
    }
}