import sys

sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
md = 10**9+7
# md = 998244353

n, k = LI()
n2 = n*2
cnt = sum(SI().count("#") for _ in range(n2))
cc = LLI(n2)

dd = []
for c in cc: dd += c
dd.sort(reverse=True)
ans = sum(dd[:cnt])

if cnt & 1 == 0:
    dd = []
    for i in range(n2):
        for j in range(n):
            dd.append(cc[i][j]+cc[i][n2-1-j])
    dd.sort(reverse=True)
    ans = max(ans, sum(dd[:cnt//2])+k)

print(ans)