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

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define UB upper_bound
#define LB lower_bound
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

int n, m, w, b;
string s[50];

struct E { int t, c, r; };
vector<E> g[2500];
bool used[2500];
const int INF = 2;

void add(int f, int t, int c) {
	int gt = g[t].size();
	int gf = g[f].size();
	g[f].PB({ t, c, gt });
	g[t].PB({ f, 0, gf });
}

int dfs(int v, int t, int f) {
	if(v == t) { return f; }
	
	used[v] = true;
	inc(i, g[v].size()) {
		E & e = g[v][i];
		if(! used[e.t] && e.c > 0) {
			int d = dfs(e.t, t, min(f, e.c));
			if(d > 0) {
				e.c -= d;
				g[e.t][e.r].c += d;
				return d;
			}
		}
	}
	
	return 0;
}

int main() {
	cin >> n >> m;
	inc(i, n) { cin >> s[i]; }
	
	int S = n * m;
	int T = S + 1;
	inc(i, n) {
	inc(j, m) {
		int p = i * n + j;
		if(s[i][j] == 'w') { w++; add(S, p, 1); }
		if(s[i][j] == 'b') { b++; add(p, T, 1); }
		int di[4] = { 1, 0, -1,  0 };
		int dj[4] = { 0, 1,  0, -1 };
		if(s[i][j] == 'w') {
			inc(k, 4) {
				int ii = i + di[k];
				int jj = j + dj[k];
				int q = ii * n + jj;
				if(inID(ii, 0, n) && inID(jj, 0, m) && s[ii][jj] == 'b') { add(p, q, 1); }
			}
		}
	}
	}
	
	int ans = 0;
	while(true) {
		inc(i, n * m) { used[i] = false; }
		int f = dfs(S, T, INF);
		ans += f;
		if(f == 0) { break; }
	}
	
	if(w < b) { swap(w, b); }
	cout << ans * 100 + (b - ans) * 10 + (w - b) << endl;
	return 0;
}