import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      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) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} Main public static void main(String[] args) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  } main {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  } final Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) final String s = scanner.nextLine(); s scanner.nextLine() scanner.nextLine scanner final String t = scanner.nextLine(); t scanner.nextLine() scanner.nextLine scanner if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    } s.length() + 1 == t.length() && t.startsWith(s) s.length() + 1 == t.length() s.length() + 1 s.length() s.length s 1 t.length() t.length t t.startsWith(s) t.startsWith t s {
      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) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} public class Main {

  public static void main(String[] args) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} Main
import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    final Scanner scanner = new Scanner(System.in);
    final String s = scanner.nextLine();
    final String t = scanner.nextLine();

    if (s.length() + 1 == t.length() && t.startsWith(s)) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
}