from collections import deque

class Dinic:
    def __init__(self, n, INF=float('inf')):
        self.n = n
        self.INF = INF
        self.pos = []
        self.G = [[] for _ in range(n)]
        self.level = None
        self.iters = None

    def add_edge(self, fr, to, cap):
        self.pos.append((fr, len(self.G[fr])))
        self.G[fr].append([cap, to, len(self.G[to])])
        self.G[to].append([0, fr, len(self.G[fr])-1])

    def bfs(self, s):
        level = [-1]*self.n
        level[s] = 0
        q = deque([s])
        while q:
            v = q.popleft()
            for cap, to, rev in self.G[v]:
                if cap > 0 and level[to] < 0:
                    level[to] = level[v]+1
                    q.append(to)
        self.level = level

    def dfs(self, v, t, flow):
        if v == t:
            return flow
        for i in range(self.iters[v], len(self.G[v])):
            self.iters[v] = i
            cap, to, rev = self.G[v][i]
            if cap > 0 and self.level[v] < self.level[to]:
                d = self.dfs(to, t, min(flow, cap))
                if d > 0:
                    self.G[v][i][0] -= d
                    self.G[to][rev][0] += d
                    return d
        return 0

    def max_flow(self, s, t):
        flow = 0
        while True:
            self.bfs(s)
            if self.level[t] < 0:
                return flow
            self.iters = [0]*self.n
            f = self.dfs(s, t, self.INF)
            while f > 0:
                flow += f
                f = self.dfs(s, t, self.INF)

n, m = map(int, input().split())
S = [input() for i in range(n)]

INF = 10**9
dinic = Dinic(n*m+2, INF)

w, b = 0, 0
s = n*m
t = n*m+1
for i in range(n):
    for j in range(m):
        if (i+j)%2 == 0 and S[i][j] != '.':
            w += 1
            dinic.add_edge(s, i*m+j, 1) # source > even
        if (i+j)%2 == 1 and S[i][j] != '.':
            b += 1
            dinic.add_edge(i*m+j, t, 1) # odd > sink

for i, row in enumerate(S):
    for j, c in enumerate(row):
        v = i*m+j
        if c == '.' or (i+j)%2 == 1:
            continue
        for di, dj in (-1, 0), (1, 0), (0, -1), (0, 1):
            ni, nj = i+di, j+dj
            if 0 <= ni < n and 0 <= nj < m:
                u = ni*m+nj
                if S[ni][nj] != '.':
                    dinic.add_edge(v, u, 1) # even > odd

f = dinic.max_flow(s, t)
ans = 0
ans += f*100
w -= f
b -= f
ans += 10*min(w, b)+(max(w, b)-min(w,b))
print(ans)