// 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;
        }
        StringBuilder str = new StringBuilder();
        str =sc.nextLine();
        
 if (str.length() < 0 || str.length() > 1000) {
            System.out.println("Invalid input");
            return;
        }

        String replaceFrom = sc.nextLine();
        String replaceTo = sc.nextLine();

        // Validate that both inputs are exactly 1 character long
        if (replaceFrom.length() != 1 || replaceTo.length() != 1) {
            System.out.println("Invalid input");
            return;
        }

        char r = replaceFrom.charAt(0);
        char c = replaceTo.charAt(0);

        System.out.println(str.replace(r, c));
    }
}