import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // write your code here
        Scanner scan = new Scanner(System.in);
        String str = scan.nextLine();
        String str2 = scan.nextLine();

        String c = str2.substring(0, str.length());


        if (str.equals(c)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

        scan.close();
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz