class BipartiteMatching:
    def __init__(self, N, M):
        self.N = N
        self.M = M
        self.pairA = [-1] * N
        self.pairB = [-1] * M
        self.edge = [[] for _ in range(N)]
        self.was = [0] * N
        self.iter = 0

    def add_edge(self, s, t):
        self.edge[s].append(t)

    def _DFS(self, s):
        self.was[s] = self.iter
        for t in self.edge[s]:
            if self.pairB[t] == -1:
                self.pairA[s] = t
                self.pairB[t] = s
                return True
        for t in self.edge[s]:
            if self.was[self.pairB[t]] != self.iter and self._DFS(self.pairB[t]):
                self.pairA[s] = t
                self.pairB[t] = s
                return True
        return False

    def bipartite_matching(self):
        res = 0
        while True:
            self.iter += 1
            found = 0
            for i in range(self.N):
                if self.pairA[i] == -1 and self._DFS(i):
                    found += 1
            if not found:
                break
            res += found
        return res


import sys
input = sys.stdin.readline
sys.setrecursionlimit(10000000)

n, m = map(int, input().split())
s = [input() for _ in range(n)]
bm = BipartiteMatching(n * m // 2 + 1, n * m // 2)
b, w = 0, 0
for i in range(n):
    for j in range(m):
        if s[i][j] == ".":
            continue
        if s[i][j] == "b":
            b += 1
        else:
            w += 1

        if (i + j) % 2:
            if j < m - 1:
                if s[i][j + 1] != ".":
                    bm.add_edge((i * m + j + 1) // 2, (i * m + j) // 2)
            if i < n - 1:
                if s[i + 1][j] != ".":
                    bm.add_edge(((i + 1) * m + j) // 2, (i * m + j) // 2)
        else:
            if j < m - 1:
                if s[i][j + 1] != ".":
                    bm.add_edge((i * m + j) // 2, (i * m + j + 1) // 2)
            if i < n - 1:
                if s[i + 1][j] != ".":
                    bm.add_edge((i * m + j) // 2, ((i + 1) * m + j) // 2)

match = bm.bipartite_matching()
b -= match
w -= match
k = min(b, m)
print(100 * match + 10 * k + (b + w - k - k))