#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for (int i = 0; i < (long long)(n); i++)
#define rep2(i, m ,n) for (int i = (m); i < (long long)(n); i++)
#define REP(i, n) for (int i = 1; i < (long long)(n); i++)
typedef long long ll;

#define updiv(N,X) (N + X - 1) / X
#define l(n) n.begin(),n.end()

#define YesNo(Q) Q==1?cout<<"Yes":cout<<"No"
using P = pair<int, int>;
using mint = modint998244353;
const int MOD = 998244353LL;
const ll INF = 999999999999LL;
vector<long long> fact, fact_inv, inv;
/*  init_nCk :二項係数のための前処理
    計算量:O(n)
*/
void init_nCk(int SIZE) {
    fact.resize(SIZE + 5);
    fact_inv.resize(SIZE + 5);
    inv.resize(SIZE + 5);
    fact[0] = fact[1] = 1;
    fact_inv[0] = fact_inv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < SIZE + 5; i++) {
        fact[i] = fact[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
        fact_inv[i] = fact_inv[i - 1] * inv[i] % MOD;
    }
}
/*  nCk :MODでの二項係数を求める(前処理 int_nCk が必要)
    計算量:O(1)
*/
long long nCk(int n, int k) {
    assert(!(n < k));
    assert(!(n < 0 || k < 0));
    return fact[n] * (fact_inv[k] * fact_inv[n - k] % MOD) % MOD;
}

long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}

 

int main() {
int n;ll b;cin>>n>>b;
vector<string>s(2*n);rep(i,2*n){cin>>s[i];}
ll v[2*n][2*n];rep(i,2*n){rep(j,2*n){cin>>v[i][j];}}
ll ls = 0;ll rs=0;
rep(i,2*n){rep(j,2*n){
    if(s[i][j]=='#'){
        if(n>j){ls++;}
        else{rs++;}
    }
}}
ll ans=0;
vector<ll>aa(4*n*n);rep(i,2*n){rep(j,2*n){aa[i*2*n+j]=v[i][j];}}
sort(l(aa));reverse(l(aa));
rep(i,ls+rs){ans += aa[i];}
if((ls+rs)%2==0){
    ll anss = 0;
    vector<ll>aaa(2*n*n);rep(i,2*n){rep(j,n){aaa[i*n+j]=v[i][j]+v[i][n*2-j-1];}}
    sort(l(aaa));reverse(l(aaa));
    rep(i,(ls+rs)/2){anss += aaa[i];}
    cout << max(ans,anss+b)<<endl;
}
else{
    cout<<ans<<endl;
}
}