#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long ll;

int main(){
    int N;
    ll K;
    cin >> N >> K;
    vector<string> S(2 * N);
    for (int i = 0; i < 2 * N; i++) cin >> S[i];

    vector<vector<ll>> C(2 * N, vector<ll>(2 * N));
    for (int i = 0; i < 2 * N; i++){
        for (int j = 0; j < 2 * N; j++){
            cin >> C[i][j];
        }
    }

    int bk_count = 0;
    for (int i = 0; i < 2 * N; i++){
        for (int j = 0; j < 2 * N; j++){
            if (S[i][j] == '#'){
                bk_count++;
            }
        }
    }
    ll INF = 100000000000000000;
    ll ans = -INF;

    for (int i = 0; i < (1 << 4 * N * N); i++){
        int pp = 0;
        for (int j = 0; j < 4 * N * N; j++){
            if ((i >> j) & 1){
                pp++;
            }
        }
        if (pp != bk_count){
            continue;
        }
        else{
            ll score = 0;
            bool symmetry = true;
            for (int j = 0; j < 4 * N * N; j++){
                int x = j / (2 * N);
                int y = j % (2 * N);
                int p = (x * 2 * N + (2 * N - 1 - y));
                if ((i >> j) & 1){
                    if (!((i >> p) & 1)){
                        symmetry = false;
                    }
                }
            }
            for (int j = 0; j < 4 * N * N; j++){
                int x = j / (2 * N);
                int y = j % (2 * N);
                if ((i >> j) & 1){
                    score += C[x][y];
                }
            }
            if (symmetry) score += K;
            ans = max(ans, score);
        }
    }
    cout << ans << endl;
}