#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T,class U> std::ostream& operator<<(std::ostream &os, std::pair<T,U> &p){ os << "(" << p.first <<", " << p.second <<")";return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;
#define MAX_V 2600

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

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

void add_edge(int from, int to, int cap){
  G[from].pb((edge){to,cap,sz(G[to])});
  G[to].pb((edge){from,0,sz(G[from])-1});
}


int dfs(int v,int t,int f){
  if(v == t){
    return f;
  }
  used[v] = true;
  rep(i,sz(G[v])){
    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 lim = INF){
  int flow = 0;
  for(;lim > 0;){
    mem(used,0);
    int f = dfs(s,t,lim);
    if(f == 0){
      break;
    }
    flow += f;
    lim -= f;
  }
  /*復元　
  for (int v = N + 1; v <= 2*N; v++) {
    rep(i,sz(G[v])){
      edge &e = G[v][i];
      ans[e.to][v-N] = e.cap;
    }
  }
  */
  return flow;
}

int N,M;
string bd[60];
int dx[] = {-1,0,0,1};
int dy[] = {0,-1,1,0};
#define XY2V(x,y) (x * 51 + y)
int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cin >> N >> M;
  map <char, int> memo;
  rep(i,N){
    cin >> bd[i];
    rep(j,M){
      memo[bd[i][j]] += 1;
    }
  }
  int b = memo['b'];
  int w = memo['w'];
  if (b > w) {
    swap(b, w);
  }
  // b <= w
  int sc = 2598;
  int fin = 2599;
  rep(i,N){
    rep(j,M){
      if (bd[i][j] == '.') {
        continue;
      }
      int v = XY2V(i,j);
      if (bd[i][j] == 'b') {
        add_edge(sc, v, 1);
        rep(k,4){
          int ni = i + dx[k];
          int nj = j + dy[k];
          if (0 <= ni && ni < N && 0 <= nj && nj < M && bd[i][j] != '.') {
            add_edge(v, XY2V(ni,nj), 1);
          }
        }
      }else{
        add_edge(v, fin, 1);
      }
    }
  }
  int f = max_flow(sc, fin);
  ll ans = 0;
  b -= f;
  w -= f;
  ans += 100 * f;
  ans += 10 * b;
  w -= b;
  ans += w;
  cout << ans << endl;
  return 0;
}