/* -*- coding: utf-8 -*-
 *
 * 2094.cc:  No.2094 Symmetry - yukicoder
 */

#include<cstdio>
#include<algorithm>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 250;
const int MAX_N2 = MAX_N * 2;
const int MAX_M = MAX_N2 * MAX_N2;

/* typedef */

typedef long long ll;

/* global variables */

char ss[MAX_N2][MAX_N2 + 4];
int cs[MAX_N2][MAX_N2], ucs[MAX_M];

/* subroutines */

/* main */

int main() {
  int n;
  ll k;
  scanf("%d%lld", &n, &k);
  int n2 = n * 2;

  int bn = 0;
  for (int i = 0; i < n2; i++) {
    scanf("%s", ss[i]);
    for (int j = 0; j < n2; j++)
      if (ss[i][j] == '#') bn++;
  }

  int m = 0;
  for (int i = 0; i < n2; i++)
    for (int j = 0; j < n2; j++)
      scanf("%d", cs[i] + j), ucs[m++] = cs[i][j];

  sort(ucs, ucs + m, greater<int>());

  ll sum = 0;
  for (int i = 0; i < bn; i++) sum += ucs[i];
  //printf("sum=%lld\n", sum);

  if (! (bn & 1)) {
    int m = 0;
    for (int i = 0; i < n2; i++)
      for (int j = 0; j < n; j++)
	ucs[m++] = cs[i][j] + cs[i][n2 - 1 - j];
    sort(ucs, ucs + m, greater<int>());

    ll sum1 = k;
    int maxi = min(bn / 2, m);
    for (int i = 0; i < maxi; i++) sum1 += ucs[i];
    sum = max(sum, sum1);
  }

  printf("%lld\n", sum);

  return 0;
}