#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int N;
ll K;
string S[500];
ll C[500][500];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>K;
	int sum=0;
	FOR(y,2*N) {
		cin>>S[y];
		FOR(x,2*N) if(S[y][x]=='#') sum++;
	}
	
	vector<ll> A,B;
	FOR(y,2*N) {
		FOR(x,2*N) {
			cin>>C[y][x];
			A.push_back(C[y][x]);
		}
		FOR(x,N) B.push_back(C[y][x]+C[y][2*N-1-x]);
	}
	sort(ALL(A));
	sort(ALL(B));
	reverse(ALL(A));
	reverse(ALL(B));
	ll ret=0;
	FOR(i,sum) ret+=A[i];
	ll ret2=-1LL<<60;
	if(sum%2==0) {
		ret2=K;
		FOR(i,sum/2) ret2+=B[i];
	}
	cout<<max(ret,ret2)<<endl;
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}