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 C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Linq;

class Program {
    static void Main(string[] args) {
        int N = Cin.Ni();
        int M = Cin.Ni();
        char[,] A = new char[N, N];
        char[,] B = new char[M, M];
        int diff = N - M;

        for (int i = 0; i < N; i++) {
            string s = Cin.Next();
            for (int j = 0; j < N; j++) {
                A[i, j] = s[j];
            }
        }
        for (int i = 0; i < M; i++) {
            string s = Cin.Next();
            for (int j = 0; j < M; j++) {
                B[i, j] = s[j];
            }
        }
        for (int i = 0; i < diff; i++) {
            for (int j = 0; j < diff; j++) {
                if (IsExist(A, B, i, j, M)) {
                    Console.WriteLine("Yes");
                    return;
                }
            }
        }
        Console.WriteLine("No");
    }
    public static bool IsExist(char[,] a, char[,] b, int startX, int startY, int bLen) {
        for (int i = 0; i < bLen; i++) {
            for (int j = 0; j < bLen; j++) {
                if (a[i + startX, j + startY] != b[i, j]) return false;
            }
        }
        return true;
    }

}


public class Cin {
    private static string[] s = new string[0];
    private static int i = 0;

    private static char[] cs = new char[] { ' ' };

    public static string Next() {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        i = 0;
        return Next();
    }

    public static int Ni() {
        return int.Parse(Next());
    }

    public static long NextLong() {
        return long.Parse(Next());
    }

    public static double NextDouble() {
        return double.Parse(Next());
    }

}