#include <bits/stdc++.h>

using namespace std;

int n, m;
int A[2500];
int B[2500];
vector <int> adj[2500];
bool visited[2500];
char board[50][50];
int dy[4] = {-1,0,1,0};
int dx[4] = {0,1,0,-1};

bool dfs(int a)
{
	visited[a] = true;
	for (auto b : adj[a])
	{
		if (B[b] == -1 || !visited[B[b]] && dfs(B[b]))
		{
			A[a] = b;
			B[b] = a;
			return true;
		}
	}

	return false;
}

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	
	cin >> n >> m;

	int cntw = 0;
	int cntb = 0;

	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			cin >> board[i][j];
			if(board[i][j]=='w') cntw++;
			else if(board[i][j]=='b') cntb++;
		}
	}

	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			if(board[i][j]=='b')
			{
				for(int k=0;k<4;k++)
				{
					int y = i + dy[k];
					int x = j + dx[k];
					if(y<0 || y>=n || x<0 || x>=m) continue;
					if(board[y][x]=='w')
					{
						adj[i*m + j].push_back(y*m + x);
					}
				}
			}
		}
	}

	int res = 0;

	memset(A, -1, sizeof(A));
	memset(B, -1, sizeof(B));

	for (int i = 0; i < n * m; i++)
	{
		if (adj[i].size() == 0) continue;
		if (A[i] == -1)
		{
			memset(visited, false, sizeof(visited));
			if (dfs(i))
			{
				res+=100;
				cntw--;
				cntb--;
			}
		}
	}

	int x = min(cntw,cntb);

	res += (10*x);
	cntw-=x;
	cntb-=x;
	res += cntw;
	res += cntb;

	cout << res << '\n';

    return 0;
}