#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> P;

#define For(i, a, b) for(int i = (a); i < (b); i++)
#define Rep(i, n) For(i, 0, (n))
#define Rrep(i, n) for(int i = (n - 1); i >= 0; i--)
#define Itr(i, c) for(typeof(c.begin()) i = c.begin(); i != c.end(); i++)
#define pb push_back

const int inf = 999999999;
const int mod = 1000000007;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

typedef struct{
	int to, cap, rev;
}edge;

vector<edge> G[2502];
bool used[2502];

void add_edge(int from, int to, int cap){
	int p = G[to].size(), q = G[from].size();
	G[from].pb((edge){to, cap, p});
	G[to].pb((edge){from, 0, q});
}

int dfs(int v, int t, int f){
	if(v == t) return f;
	used[v] = true;
	for(int i = 0; i < G[v].size(); i++){
		edge &e = G[v][i];
		if(!used[e.to] && e.cap > 0){
			int d = dfs(e.to, t, min(f, e.cap));
			if(d > 0){
				e.cap -= d;
				G[e.to][e.rev].cap += d;
				return d;
			}
		}
	}
	return 0;
}

int max_flow(int s, int t){
	int flow = 0;
	while(1){
		Rep(i, sizeof(used)/sizeof(*used)){
			used[i] = false;
		}
		int f = dfs(s, t, inf);
		if(f == 0) return flow;
		flow += f;
	}
}

int main(){
	int n, m, b = 0, w = 0; cin >> n >> m;
	string c[n];
	Rep(i, n){
		cin >> c[i];
		Rep(j, m){
			if(c[i][j] == 'w'){
				w += 1;
				add_edge(2500, i * m + j, 1);
			}else if(c[i][j] == 'b'){
				b += 1;
				add_edge(i * m + j, 2501, 1);
			}
		}
	}
	Rep(i, n){
		Rep(j, m){
			Rep(k, 4){
				int s = i + dx[k], t = j + dy[k];
				if(s >= 0 && s < n && t >= 0 && t < m){
					if(c[i][j] == 'w' && c[s][t] == 'b'){
						add_edge(i * m + j, s * m + t, 1);
					}
				}
			}
		}
	}
	int f = max_flow(2500, 2501);
	b -= f; w -= f;
	cout << f * 100 + min(b, w) * 10 + (max(b, w) - min(b, w)) << endl;
	return 0;
}