import java.util.Scanner;

public class Main{

    public static void main(String []args){
        Scanner sc = new Scanner(System.in);
        String a="";
        String b="";
        a=sc.nextLine();
        b=sc.nextLine();

        if(a.equals(b.substring(0,a.length()))){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }


    }

}
/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