using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static string[] SList(int n) => Enumerable.Repeat(0, n).Select(_ => ReadLine()).ToArray();
    static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, k) = ((int)c[0], c[1]);
        n <<= 1;
        var b = 0;
        for (var i = 0; i < n; ++i)
        {
            b += ReadLine().Count(c => c == '#');
        }
        var clist = new long[n * n];
        var slist = new long[n * n / 2];
        for (var i = 0; i < n; ++i)
        {
            c = NList;
            for (var j = 0; j < n; ++j)
            {
                clist[i * n + j] = c[j];
                if (j < n / 2) slist[i * n / 2 + j] += c[j];
                else slist[i * n / 2 + n - j - 1] += c[j];
            }
        }
        Array.Sort(clist, (l, r) => r.CompareTo(l));
        Array.Sort(slist, (l, r) => r.CompareTo(l));
        var res = 0L;
        for (var i = 0; i < b; ++i) res += clist[i];
        if (b % 2 == 0)
        {
            var sub = k;
            for (var i = 0; i < b / 2; ++i) sub += slist[i];
            res = Math.Max(res, sub);
        }
        WriteLine(res);
    }
}