#include <bits/stdc++.h>
#include <sys/time.h>


using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<long>;
using vvl = vector<vl>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vb = vector<bool>;
using vvb = vector<vb>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vstr = vector<string>;
constexpr ll INF_LL=1LL<<62;
constexpr int INF_I=1LL<<30;
#define rep(i,n) for(int i=0; i<((int)(n)); i++)
#define reps(i,n) for(int i=1; i<=((int)(n)); i++)
#define vector_cin(x) for(auto &n : (x)) cin >> n
#define ALL(x) (x).begin(), (x).end()
#define YesNo(x) ((x) ? "Yes": "No")
#define pb emplace_back
#define to_lower(S) transform(ALL((S)), (S).begin(), ::tolower)
#define to_upper(S) transform(ALL((S)), (S).begin(), ::toupper)
template <typename T>
bool chmax(T &a, const T& b) {if (a < b){a = b;return true;}return false;}

template <typename T>
bool chmin(T &a, const T& b) {if (a > b){a = b;return true;}return false;}
ll ceilint(ll x, ll y) {return (x + y - 1) / y;}
void Main();
int main() {std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);std::cout << std::fixed << std::setprecision(15);Main();return 0;}

//-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

void Main() {
    ll N, K;
    cin >> N >> K;
    vstr S(N * 2);
    vector_cin(S);
    vvll C(2 * N, vll(2 * N));
    map<pll, ll> black, white;
    vll sum;
    ll ans = 0, size_b = 0, size_w = 0;
    rep(i, 2 * N)
        rep(j, 2 * N)
            cin >> C[i][j];
    rep(i, 2 * N) {
        rep(j, 2 * N) {
            if (S[i][j] == '#') {
                black[make_pair(i, j)] = C[i][j];
                ans += C[i][j];
                size_b++;
            } else {
                white[make_pair(i, j)] = C[i][j];
                size_w++;
            }
            if (j <= N - 1) {
                sum.pb(C[i][j] + C[i][2 * N - j - 1]);
            }
        }
    }
    while (!white.empty() && !black.empty())
    {
        pair<pll, ll> w = *white.begin(), b = *black.begin();
        for (auto w_ : white)
        {
            if (w.second < w_.second) {
                w.first = w_.first;
                w.second = w_.second;
            }
        }
        for (auto b_ : black)
        {
            if (b.second > b_.second) {
                b.first = b_.first;
                b.second = b_.second;
            }
        }
        
        white.erase(w.first);
        black.erase(b.first);
        white[b.first] = b.second;
        black[w.first] = w.second;
        if ((w.second) - (b.second) <= 0) break;
        else ans += (w.second) - (b.second);
    }
    ll num = 0;
    if (size_w == size_b && size_w % 2 == 0) {
        sort(ALL(sum), greater<ll>());
        rep(i, size_b / 2) num += sum[i];
        num += K;
    }
    if (size_w ==0 || size_b == 0) {
        num = 0;
        if (size_w == 0) {
            rep(i, 2 * N) rep(j, 2 * N) num += C[i][j];
        }
        num += K;
    }
    cout << max(ans, num) << endl;
}