#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <deque>
#include <atcoder/modint>

using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)

const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;

int main(){
    int N; cin >> N;
    i64 K; cin >> K;
    int Bcnt = 0;
    rep(i,N*2){ string s; cin >> s; for(char c : s) if(c == '#') Bcnt++; }
    vector<i64> C(N*N*4);
    vector<i64> C2(N*N*2);
    rep(i,2*N) rep(j,2*N){
        int c; cin >> c;
        C[2*N*i+j] += c;
        C2[N*i+min(j,2*N-1-j)] += c;
    }
    sort(C.begin(), C.end(), greater<i64>());
    sort(C2.begin(), C2.end(), greater<i64>());
    i64 ans1 = 0;
    rep(i,Bcnt) ans1 += C[i];
    if(Bcnt % 2 == 0){
        i64 ans2 = K;
        rep(i,Bcnt/2) ans2 += C2[i];
        ans1 = max(ans1, ans2);
    }
    cout << ans1 << endl;
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;