#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
#define REP(i,n) for(int i=0;i<(n);i++)
#define ALL(v) v.begin(),v.end()
template<typename T> bool chmax(T &x, const T &y) {return (x<y)?(x=y,true):false;};
template<typename T> bool chmin(T &x, const T &y) {return (x>y)?(x=y,true):false;};
constexpr ll MOD=998244353;
constexpr ll INF=2e18;

int main(){
    ll n, k; cin >> n >> k;
    ll m=n*2;
    vector<string> s(m);
    REP(i,m) cin >> s[i];
    VVI c(m,VI(m));
    REP(i,m)REP(j,m) cin >> c[i][j];
    ll cnt=0;
    REP(i,m)REP(j,m){
        if(s[i][j]=='#')
            cnt++;
    }
    ll ans=-INF;
    if(cnt%2==0){
        VI a;
        REP(i,m)REP(j,n){
            a.push_back(c[i][j]+c[i][m-1-j]);
        }
        sort(ALL(a),greater<ll>());
        ll sum=k;
        REP(i,cnt/2) sum+=a[i];
        chmax(ans,sum);
    }
    VI b;
    REP(i,m)REP(j,m) b.push_back(c[i][j]);
    sort(ALL(b),greater<ll>());
    ll sum=0;
    REP(i,cnt) sum+=b[i];
    chmax(ans,sum);
    cout << ans << endl;
    return 0;
}