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();
		if (T.matches(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) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();
		if (T.matches(S+".")) {
			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();
		if (T.matches(S+".")) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	} main {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();
		if (T.matches(S+".")) {
			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 if (T.matches(S+".")) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		} T.matches(S+".") T.matches T S+"." 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) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();
		if (T.matches(S+".")) {
			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();
		if (T.matches(S+".")) {
			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();
		if (T.matches(S+".")) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
}