#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <deque>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <set>
#include <map>
#include <ctime>
#include <stack>
#include <functional>
#include <cstdio>
#include <string>
#include <iostream>
#include <limits>
#include <stdexcept>
#include <numeric>
#include <fstream>
#include <chrono>
#include <utility>
#include <cassert>
#include <random>
#include <time.h>
using namespace std;
// /*
#include <atcoder/all>
using namespace atcoder;
using mint =modint998244353;
//using mint =modint1000000009;
//using mint =modint1000000007;
#define ip(x) is_prime_constexpr(x)
istream &operator>>(istream &is, mint &a) { int v; cin >> v; a = v; return is; }
ostream &operator<<(ostream &os, const mint &a) { return os << a.val(); }
// */
template<typename T> istream &operator>>(istream &is, vector<T> &v) { for (auto &e : v) is >> e; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double LD;
typedef double D;
typedef pair<ll,ll> P;
typedef map<ll,ll> M;
void tatananonano() {
ios::sync_with_stdio(false);
std::cin.tie(nullptr);
cout<< fixed << setprecision(10);
}
#define LL(...) ll __VA_ARGS__; IN(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; IN(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;IN(__VA_ARGS__)
template <class T> void scan(T &a) { cin >> a; }
void IN() {}
template <class Head, class... Tail> void IN(Head &head, Tail &...tail) {scan(head);IN(tail...);}
#define rep(i,n) for(ll i=0;i<n;i++)
#define rrep(i,n) for(ll i=1;i<n;i++)
#define jep(i, a, n)for (ll i =(ll)a; i<(ll)n;++i)
#define drep2(i, m, n) for (int i = (n)-1; i >= (m); --i)
#define drep(i, n) drep2(i,0,n)
#define fore(i,a) for(const auto &i:a)
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define uni(x) sort(all(x));x.erase(unique(all(x)),x.end())
#define TFU(s) transform(all(s),begin(s),::toupper);//大文字にする
#define TFL(s) transform(all(s),begin(s),::tolower);//小文字にする
#define replace(s,a,A) replace(s,'a','A')//str(s)のaをAにする
#define ROT(s,i) rotate(s.begin(),s.begin()+i,s.end())//sのi番目から後ろを前にする
#define PQ priority_queue
#define PQD PQ<P,vector<P>,greater<P>>//小さい順に吐く
#define PQS PQ<ll,vec,greater<ll>>//小さい順に吐く
#define fi first
#define se second
#define bit(n,k) ((n>>k)&1LL)
#define printd(n,x) cout<<fixed<<setprecision(n)<<x<<endl
#define cinv(a,n); rep(i,n){cin>>a[i];}
#define popcount(n) __builtin_popcountll(n)
template<class T> inline bool chmax(T& a,T b){if(a < b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T& a,T b){if(a > b){a=b;return 1;}return 0;}
typedef vector<ll> vec;
typedef vector<vec> mat;
//const ll mod = 1000000009;
const ll mod = 998244353;
//const ll mod = 1000000007;
const auto INF = (1LL<<(60));
ll modpow(ll a,ll n,ll mod){if(mod==1)return 0;ll ret=1;ll p=a%mod;while(n){if(n&1)ret=ret*p%mod;p=p*p%mod;n>>=1;}return ret; }
M factor(ll n) {M ret;for(ll i=2;i*i<=n;i++){while(n%i==0){ret[i]++;n /= i;}}if(n != 1){ret[n]=1;}return ret;}//素因数分解
vec divisor(ll n){vec K;for(ll i=1;i*i<=n;i++){if(n%i==0){K.pb(i);if(i*i!=n)K.pb(n/i);}}sort(all(K));return K;}//約数列挙 














ll dx[4]={0,1,0,-1},dy[4]={-1,0,1,0};
int main(){
tatananonano();
LL(n,m);
vector<string> s(n);
rep(i,n){cin>>s[i];}
vector<P> w,b;
rep(i,n){
rep(j,m){
if(s[i][j]=='w'){w.pb({i,j});}
if(s[i][j]=='b'){b.pb({i,j});}
}
}
mf_graph<ll> mf(n*m+2);
rep(i,w.size()){mf.add_edge(n*m,(w[i].fi*m)+w[i].se,1);}
rep(i,b.size()){mf.add_edge((b[i].fi*m)+b[i].se,n*m+1,1);}
rep(i,w.size()){
auto [u,v]=w[i];
rep(j,4){
if(0<=min(u+dx[j],v+dy[j]) and u+dx[i]<n and v+dy[j]<m)if(s[u+dx[j]][v+dy[j]]=='b'){
mf.add_edge(u*m+v,(u+dx[j])*m+(v+dy[j]),1);
}
}
}
auto key=mf.flow(n*m,n*m+1);
auto mx=max(w.size(),b.size());
auto mn=min(w.size(),b.size());
cout<<(key*100)+(mn-key)*10+(mx-mn)<<'\n';
}