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();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			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();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			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();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			System.out.println("Yes");
		else
			System.out.println("No");

	} main {
		Scanner sc = new Scanner(System.in);

		String s = sc.next();
		String t = sc.next();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			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 String newStr = s + t.charAt(t.length() -1); newStr s + t.charAt(t.length() -1) s t.charAt(t.length() -1) t.charAt t t.length() -1 t.length() t.length t 1 if (t.equals(newStr))
			System.out.println("Yes");
		else
			System.out.println("No"); t.equals(newStr) t.equals t newStr 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 t = sc.next();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			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();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			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();

		String newStr = s + t.charAt(t.length() -1);
		if (t.equals(newStr))
			System.out.println("Yes");
		else
			System.out.println("No");

	}
}
