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