#include <stdio.h>
#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 4000000000000000001


int main(){
	
	long long n,k;
	cin>>n>>k;
	n *= 2;
	vector<string> s(n);
	rep(i,n)cin>>s[i];
	long long w = 0;
	rep(i,n){
		rep(j,n){
			if(s[i][j]=='.')w++;
		}
	}
	
	vector c(n,vector<long long>(n));
	rep(i,n){
		rep(j,n)cin>>c[i][j];
	}
	long long ans = -Inf64;
	
	{
		long long t = 0;
		vector<long long> diff;
		rep(i,n){
			rep(j,n/2){
				t += c[i][j];
				diff.push_back(-c[i][j]);
				t += c[i][n-1-j];
				diff.push_back(-c[i][n-1-j]);
			}
		}
		sort(diff.rbegin(),diff.rend());
		rep(i,w)t += diff[i];
		ans = max(ans,t);
	//	cout<<ans<<endl;
	}
	{
		long long t = 0;
		vector<long long> diff;
		rep(i,n){
			rep(j,n/2){
				t += c[i][j] + c[i][n-1-j];
				diff.push_back(-(c[i][j]+c[i][n-1-j]));
			}
		}
		sort(diff.rbegin(),diff.rend());
		if(w%2==0){
			rep(j,w/2){
				t += diff[j];
			}
			ans = max(ans,t+k);
		}
		
	}
	
	cout<<ans<<endl;
	
	return 0;
}