#include <bits/stdc++.h>
using namespace std;
const int maxn = 1005;
vector<int> z[10005];
int n1, n2, m, ans, N, M;
void add_edge(int s,int e) 
{
	z[s].push_back(e);
}
bool vis[10005];
char choco[105][105];
int result[10005];
bool dfs(int i)
{
	for (int k=0;k<z[i].size();k++)
	{
		int j = z[i][k];
		if (!vis[j])
		{
			vis[j] = true;
			if (!result[j] || dfs(result[j]))
			{
				result[j] = i;
				return true;
			}
		}
	}
	return false;
}
int zb(int x, int y)
{
	return M*(x-1)+y;
}
int main()
{
	cin >> N >> M;
	for (int i = 1;i <= N;i++)
	{
		for (int j = 1;j <= M;j++)
		{
			cin >> choco[i][j];
		}
	}
	for (int i = 1;i <= N;i++)
	{
		for (int j = 1;j <= M;j++)
		{
			if(choco[i][j] == 'b')
			{
				n1++;
				if(choco[i][j+1]=='w')
				{
					add_edge(n1, zb(i, j+1));
				}
				if(choco[i+1][j]=='w')
				{
					add_edge(n1, zb(i+1, j));
				}
				if(choco[i][j-1]=='w')
				{
					add_edge(n1, zb(i, j-1));
				}
				if(choco[i-1][j]=='w')
				{
					add_edge(n1, zb(i-1, j));
				}
			}
			if(choco[i][j] == 'w') n2++;
		}
	}
	for (int i=1;i<=n1;i++)
	{ 
		memset(vis,false,sizeof(vis));
		if (dfs(i)) ans++;
	}
	if(n1 > n2) cout << ans*100 + (n2-ans)*10 + n1-n2;
	if(n1 <= n2) cout << ans*100 + (n1-ans)*10 + n2-n1;
}