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

#define int long long
typedef vector<int>vint;
typedef pair<int,int>pint;
typedef vector<pint>vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define all(v) (v).begin(),(v).end()
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define fi first
#define se second
template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;}
template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;}

#define MAX_V 2500

int V;
std::vector<int> G[MAX_V];
int match[MAX_V];
int used[MAX_V];

void add_edge(int u, int v) {
  G[u].push_back(v);
  G[v].push_back(u);
}


bool dfs(int v) {
  used[v] = true;

  for (int i = 0; i < G[v].size(); i ++) {
    int u = G[v][i], w = match[u];

    if (w < 0 || ! used[w] && dfs(w)) {
      match[v] = u;
      match[u] = v;

      return true;
    }
  }

  return false;
}

int bipartite_matching() {
  int res = 0;

  memset(match, -1, sizeof(match));

  for (int v = 0; v < V; v ++) {
    if (match[v] < 0) {
      memset(used, 0, sizeof(used));

      if (dfs(v))
	res ++;
    }
  }
  return res;
}

int H,W;
char fld[55][55];

signed main(){
    cin>>H>>W;
    rep(i,H)cin>>fld[i];

    V=2500;
    int cntW=0,cntB=0;
    rep(i,H)rep(j,W){
        if(fld[i][j]=='.')continue;
        if(fld[i][j]=='b')cntB++;
        else cntW++;

        if(i+1<H&&fld[i+1][j]!='.')add_edge(i*W+j,(i+1)*W+j);
        if(j+1<W&&fld[i][j+1]!='.')add_edge(i*W+j,i*W+j+1);
    }

    int tmp=bipartite_matching();

    cntW-=tmp;cntB-=tmp;
    cout<<tmp*100+min(cntW,cntB)*10+abs(cntW-cntB)<<endl;
    return 0;
}