import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

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

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc String b = sc.next(); b sc.next() sc.next sc sc.close() sc.close sc String result = "No"; result "No" if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        } a.equals(b.substring(0, b.length()-1)) a.equals a b.substring(0, b.length()-1) b.substring b 0 b.length()-1 b.length() b.length b 1 {
            result = "Yes";
        } result = "Yes" result "Yes" System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        String b = sc.next();
        sc.close();

        String result = "No";
        if (a.equals(b.substring(0, b.length()-1))) {
            result = "Yes";
        }
        System.out.println(result);
    }
}