#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define Rep(i,h,t) for(int i=(int)h;i<(int)t;i++)
#define Rrep(i,n) for(int i=(int)n;i>=0;i--)
#define RRep(i,h,t) for(int i=(int)h;i>=(int)t;i--)
#define UNIQ(v) v.erase(unique(v.begin(),v.end()),v.end());
#define pb push_back
#define Fi first
#define Se second

template<typename T>
bool chmax(T& vmax,const T& v)
{
    if(vmax<v)
    {
        vmax=v;
        return true;
    }
    return false;
}

template<typename T>
bool chmin(T& vmin,const T& v)
{
    if(vmin>v)
    {
        vmin=v;
        return true;
    }
    return false;
}

using namespace std;

using ll=long long;
using lb=long double;
using veci=vector<int>;
using vec2i=vector<vector<int>>;
using vecll=vector<ll>;
using vec2ll=vector<vector<ll>>;
using p2i=pair<int,int>;
using p2ll=pair<ll,ll>;
using m2i=map<int,int>;
using m2ll=map<ll,ll>;
using msi=map<string,int>;


ll gcd(ll a,ll b)
{
    if(b==0)
    {
        return a;
    }
    return gcd(b,a%b);
}

ll lcm(ll a,ll b)
{
    return ll(a/gcd(a,b))*b;
}

void yn_out(bool b,string yes_out="Yes",string no_out="No")
{
    cout<<(b ? yes_out : no_out)<<endl;
}

ll ceilll(ll a,ll b)
{
    return (a+b-1)/b;
}

const int MOD=1e9+7;
//const int MOD=998244353;
const int dirx[4]={1,0,-1,0};
const int diry[4]={0,1,0,-1};


bool is_symmetry(vector<string> S,int N){
    rep(i,N){
        rep(j,N){
            if(S[i][j]!=S[i][2*N-1-j]) {
                return false;
            }
        }
    }
    return true;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    //cout<<fixed<<setprecision(9);
    int N;
    ll K;
    cin>>N>>K;
    vector<string> S(2*N);
    rep(i,2*N){
        cin>>S[i];
    }
    // W:昇順 B:降順
    set<pair<ll,int>> W,B;

    vec2ll C(2*N,vecll(2*N));
    ll ans=-1e16;
    ll sum=0;
    rep(i,2*N){
        rep(j,2*N){
            cin>>C[i][j];
            if(S[i][j]=='.'){
                W.insert({-C[i][j],i*2*N+j});
            }
            else{
                B.insert({C[i][j],i*2*N+j});
                sum+=C[i][j];
            }
        }
    }
    if(is_symmetry(S,N)){
        ans=sum+K;
    }
    else{
        ans=sum;
    }
    rep(i,2*N){
        auto [w,wp]=*W.begin();
        auto [b,bp]=*B.begin();
        W.erase(W.begin());
        B.erase(B.begin());
        w*=-1;
        if(b>=w){
            break;
        }
        sum+=w-b;
        W.insert({-b,bp});
        B.insert({w,wp});
        swap(S[wp/(2*N)][wp%(2*N)],S[bp/(2*N)][bp%(2*N)]);
        if(is_symmetry(S,N)){
            chmax(ans,sum+K);
        }
        else{
            chmax(ans,sum);
        }
    }
    cout<<ans<<endl;
    return 0;
}