import java.util.*;
public class replace
{
    public static void main(String[]args)
    {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        char a = sc.next().charAt(0);
        char b = sc.next().charAt(0);
        if(character.isletter(a) || character.isletter(b))
        {
            System.out.println("Invalid input");
            return;
        }
        for (int i=0;i<s.length();i++)
        {
            char ch = s.charAt(i);
            if(ch == a)
            {
                System.out.print(b);
            }
            else
            {
                System.out.print(ch);
            }
        }
    }
}