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 Ruby (2.3.3) (judge verdict: Wrong Answer)

# frozen_string_literal: true

def select_index(str, substr)
  i = 0
  indexs = []
  loop do
    index = str.index(substr, i)
    return indexs unless index

    indexs << index
    i = index + 1
  end

  indexs
end

n, m = gets.split(' ').map!(&:to_i)

a = []
b = []
n.times { a << gets.chomp! }
m.times { b << gets.chomp! }

ans = 'No'

first_line = b.shift
a.each.with_index do |a_s, i|
  select_index(a_s, first_line).each do |index|
    match = true
    b.each.with_index(1) do |b_s, j|
      break unless a[i + j]

      if b_s != a[i + j].slice(index, m)
        match = false
        break
      end
    end
    if match
      ans = 'Yes'
      break
    end
  end
  break if ans == 'Yes'
end

puts ans