Problem:
Score : 200 points

Problem Statement

You are given an image A composed of N rows and N columns of pixels, and a template image B composed of M rows and M columns of pixels.

A pixel is the smallest element of an image, and in this problem it is a square of size 1×1.

Also, the given images are binary images, and the color of each pixel is either white or black.

In the input, every pixel is represented by a character: . corresponds to a white pixel, and # corresponds to a black pixel.

The image A is given as N strings A_1,...,A_N.

The j-th character in the string A_i corresponds to the pixel at the i-th row and j-th column of the image A (1≦i,j≦N).

Similarly, the template image B is given as M strings B_1,...,B_M.

The j-th character in the string B_i corresponds to the pixel at the i-th row and j-th column of the template image B (1≦i,j≦M).

Determine whether the template image B is contained in the image A when only parallel shifts can be applied to the images.

Constraints

1≦M≦N≦50

A_i is a string of length N consisting of # and ..

B_i is a string of length M consisting of # and ..

Input

The input is given from Standard Input in the following format:

N M
A_1
A_2
:
A_N
B_1
B_2
:
B_M

Output

Print Yes if the template image B is contained in the image A. Print No otherwise.

Sample Input 1

3 2
#.#
.#.
#.#
#.
.#

Sample Output 1

Yes

The template image B is identical to the upper-left 2 × 2 subimage and the lower-right 2 × 2 subimage of A. Thus, the output should be Yes.

Sample Input 2

4 1
....
....
....
....
#

Sample Output 2

No

The template image B, composed of a black pixel, is not contained in the image A composed of white pixels.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		try {
			int n = sc.nextInt();
			int m = sc.nextInt();
			sc.nextLine();

			List<String> a = new ArrayList<String>();
			for (int i = 0; i < n; i++) {
				a.add(sc.nextLine());
			}
			List<String> b = new ArrayList<String>();
			for (int i = 0; i < m; i++) {
				b.add(sc.nextLine());
			}

			for (int i = 0; i < n - m; i++) {
				String ai = a.get(i);
				int index = ai.indexOf(b.get(0));
				if (m == 1 && index != -1) {
					System.out.println("Yes");
					return;
				}
				while (index != -1) {
					boolean match = true;
					for (int k = 1; k < m; k++) {
						if (!a.get(i + k).substring(index, index + m).equals(b.get(k))) {
							match = false;
							break;
						}
					}
					if (match) {
						System.out.println("Yes");
						return;
					}
					if (index == ai.length() - 1) {
						break;
					}
					ai = ai.substring(index + 1);
					index = ai.indexOf(b.get(0));
				}
			}

			System.out.println("No");

		} finally {
			sc.close();
		}
	}
}