import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        String s=sc.nextLine();
        String c1str=sc.nextLine();
        String c2str=sc.nextLine();
        if(c1str.length() !=1 || c2str.length() !=1){
            System.out.println("Invalid input");
            return;
        }
        else{
            
            String modifiedString =s.replace(old.charAt(0),c2str.charAt(0));
            System.out.println(modifiedString);
        }
    }
}