import java.util.*;

public class Main{
    
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            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.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            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.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }
        
    } main {
        
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }
        
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.nextLine(); s sc.nextLine() sc.nextLine sc String t = sc.nextLine(); t sc.nextLine() sc.nextLine sc int n = s.length(); n s.length() s.length s s = s + t.charAt(n) s s + t.charAt(n) s t.charAt(n) t.charAt t n if(s.equals(t)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        } s.equals(t) s.equals s t {
            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.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            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.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            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.nextLine();
        String t = sc.nextLine();
        int n = s.length();
        
        s = s + t.charAt(n);
        
        // System.out.println(s+" "+t);
        
        if(s.equals(t)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }
        
    }
    
}