import java.util.Scanner;
 
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String S=sc.next();
    String T=sc.next();
    int X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    }
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String S=sc.next();
    String T=sc.next();
    int X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	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 X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	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 X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	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 X=T.length(); X T.length() T.length T String Z=T.substring(0,X-1); Z T.substring(0,X-1) T.substring T 0 X-1 X 1 if(S.equals(Z)) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    } S.equals(Z) S.equals S Z {
    	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 public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String S=sc.next();
    String T=sc.next();
    int X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    }
  }
} public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String S=sc.next();
    String T=sc.next();
    int X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    }
  }
} Main
import java.util.Scanner;
 
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String S=sc.next();
    String T=sc.next();
    int X=T.length();
    String Z=T.substring(0,X-1);
    if(S.equals(Z)) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    }
  }
}