import java.util.Scanner;

class Main{
	public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      
 		String S = sc.next();
      	String T = sc.next();
      
      	int a = S.length();
       	String b = T.substring(0,a);
 
      if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      }
    }
} import java.util.Scanner; Scanner java.util class Main{
	public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      
 		String S = sc.next();
      	String T = sc.next();
      
      	int a = S.length();
       	String b = T.substring(0,a);
 
      if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      }
    }
} Main public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      
 		String S = sc.next();
      	String T = sc.next();
      
      	int a = S.length();
       	String b = T.substring(0,a);
 
      if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      }
    } main {
      Scanner sc = new Scanner(System.in);
      
 		String S = sc.next();
      	String T = sc.next();
      
      	int a = S.length();
       	String b = T.substring(0,a);
 
      if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc String T = sc.next(); T sc.next() sc.next sc int a = S.length(); a S.length() S.length S String b = T.substring(0,a); b T.substring(0,a) T.substring T 0 a if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      } S.equals(b) S.equals S b {
      	System.out.println("Yes");
      } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
      	System.out.println("No");
      } System.out.println("No") System.out.println System.out System System.out "No" String[] args args
import java.util.Scanner;

class Main{
	public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      
 		String S = sc.next();
      	String T = sc.next();
      
      	int a = S.length();
       	String b = T.substring(0,a);
 
      if(S.equals(b)){
      	System.out.println("Yes");
      }else{
      	System.out.println("No");
      }
    }
}