#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
using namespace std;

bool is_symmetry(const vector<string> &grid, int N) {
    for(int i = 0; i < 2 * N; i++) {
        for(int j = 0; j < N; j++) {
            if(grid[i][j] != grid[i][2 * N - j]) return false;
        }
    }
    return true;
}

int main() {
    int N; cin >> N;
    long long K; cin >> K;
    bool symmmetrize = false;
    vector<string> grid(2 * N);
    long long C[2 * N][2 * N];
    int n_black = 0;
    for(int i = 0; i < 2 * N; i++) {
        cin >> grid[i];
        for(int j = 0; j < 2 * N; j) {
            if(grid[j] == "#") n_black++;
        }
    }
    if(n_black % 2 == 0) symmmetrize = true;
    vector<long long> vals, vals2;
    for(int i = 0; i < 2 * N; i++) {
        for(int j = 0; j < 2 * N; j++) {
            cin >> C[i][j];
            vals.push_back(C[i][j]);
            if(j > N) {
                vals2.push_back(C[i][j] + C[i][2 * N - j]);
            }
        }
    }
    sort(vals.rbegin(), vals.rend());
    sort(vals2.rbegin(), vals2.rend());
    long long ans = 0;
    long long ans2 = 0;
    for(int i = 0; i < n_black; i++) ans += vals[i];
    if(is_symmetry(grid, N)) ans += K;
    if(symmmetrize) {
        for(int i = 0; i < n_black / 2; i++) {
            ans2 += vals2[i];
        }
        ans2 += K;
    }
    cout << max(ans, ans2) << endl;
}