#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using pll = pair<ll,ll>;
#define rep(i,n) for (int i = 0; i < (n); i++)
#define rep1(i,n) for (int i = 1; i <= (n); i++)
#define all(a) begin(a), end(a)
// aよりもbが大きいならばaをbで更新する
// (更新されたならばtrueを返す)
template <typename T>
bool chmax(T &a, const T& b) {
  if (a < b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}
// aよりもbが小さいならばaをbで更新する
// (更新されたならばtrueを返す)
template <typename T>
bool chmin(T &a, const T& b) {
  if (a > b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}

ll modpow(ll a, ll b, ll m) {
	ll p = a;
	ll ans = 1;
	rep(i,32) {
		if ((b & (0x01 << i)) != 0) {
			ans *= p;
			ans %= m;
		}
		p *= p;
		p %= m;
	}
	return (ans);
}

ll pow(ll a, ll b) {
	ll p = a;
	ll ans = 1;
	rep(i,32) {
		if ((b & (0x01 << i)) != 0) {
			ans *= p;
		}
		p *= p;
	}
	return (ans);
}

ll Division(ll a, ll b, ll m) {
	return ((a * modpow(b, m - 2, m)) % m);
}

struct V {
	int x, y;
	V(int x=0, int y=0): x(x), y(y) {}
	V operator-(const V &a) const {
		return V(x-a.x, y-a.y);
	}
	int cross(const V &a) const {
		return x*a.y - y*a.x;
	}
	int ccw(const V &a) const {
		int area = cross(a);
		if (area > 0) return +1; // ccw
		if (area < 0) return -1; // cw
		return 0; // collinear
	}
};

/*
	2147483648 int max
	1000000000 1e9
	9223372036854775807 ll max
	1000000000000000000 1e18
*/

int main() {
	int N;
	cin >> N;
	ll K;
	cin >> K;
	vector<string> s(2*N);
	rep(i,2*N) cin >> s[i];
	ll white = 0, black = 0;
	rep(i,2*N)rep(j,2*N) {
		if (s[i][j] == '#') black++;
		else white++;
	}
	vector<vector<ll>> c(2*N);
	vector<pair<ll, pair<ll,ll>>> ar;
	rep(i,2*N)rep(j,2*N) {
		ll a;
		cin >> a;
		c[i].push_back(a);
		ar.push_back({a, {i,j}});
	}
	bool isable = false;
	if (black%2==0 && white%2==0) isable = true;

	ll ans = 0;
	sort(all(ar), greater());
	rep(i,black) ans += ar[i].first;
	if (!isable) {
		cout << ans << endl;
		return 0;
	}

	// シンメトリーの最大
	ll x = 0;
	rep(i,black/2) {
		x += (ar[i].first + c[ar[i].second.first][2*N-1-ar[i].second.second]);
	}
	ans = max(ans, x+K);
	cout << ans << endl;
	return 0;
}