#include<bits/stdc++.h>
#define int long long
using namespace std;
struct node{
	int to,next;
}a[200010];
int head[200010],in[10010],cnt,ans,x,y;
bool f[10010];
char c[1010][1010];
queue<int> q;
priority_queue<pair<int,int> > que;
void add(int u,int v)
{
	a[++cnt].to=v;
	a[cnt].next=head[u];
	head[u]=cnt;
}
void add_edge(int u,int v)
{
	in[u]++;
	in[v]++;
	//cout<<u<<" "<<v<<endl; 
	add(u,v);
	add(v,u);

}
void clear(int x)
{
	for(int i=head[x];i;i=a[i].next)
	{
		int v=a[i].to;
		if(in[v]!=0)
			in[v]--;
		if(in[v]==1)
			q.push(v);
	}
}
void pop(int x)
{
	for(int i=head[x];i;i=a[i].next)
	{
		int v=a[i].to;
		if(in[v]!=0)
			in[v]--;
		if(in[v]!=0)
			que.push({-in[v],v});
	}
}
signed main()
{
	int n,m,k;
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=m;j++)
		{
			cin>>c[i][j];
			if(c[i][j]=='w')
				x++;
			else if(c[i][j]=='b')
				y++;
		}
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=m;j++)
		{
			if(i+1<=n&&c[i+1][j]!='.'&&c[i][j]!='.'&&c[i+1][j]!=c[i][j])
				add_edge((i-1)*m+j,i*m+j);//,cout<<i<<" "<<j<<" "<<i+1<<" "<<j<<" "<<(i-1)*n+j<<" "<<i*n+j<<endl;
			if(j+1<=m&&c[i][j+1]!='.'&&c[i][j]!='.'&&c[i][j]!=c[i][j+1])
				add_edge((i-1)*m+j,(i-1)*m+j+1);//,cout<<i<<" "<<j<<" "<<i<<" "<<j+1<<" "<<(i-1)*n+j<<" "<<(i-1)*n+j+1<<endl;
		}
	}
	for(int i=1;i<=n*m;i++)
	{
		if(in[i]==1)
			q.push(i);
	}
	while(!q.empty())
	{
		int u=q.front();
		q.pop();
		if(!in[u])
			continue;
		for(int i=head[u];i;i=a[i].next)
		{
			int v=a[i].to;
			if(!in[v])
				continue;
			in[u]=in[v]=0;
			clear(u);
			clear(v);
			ans+=100;
			x--;
			y--;
			break;
		}
		//cout<<ans<<" "<<x<<" "<<y<<endl;
	}
	for(int i=1;i<=n*m;i++)
	{
		if(in[i]>1)
		{
			que.push({0,i});
			while(!que.empty())
			{
				int u=que.top().second;
				que.pop();
				if(!in[u])
					continue;
				for(int i=head[u];i;i=a[i].next)
				{
					int v=a[i].to;
					//cout<<i<<" "<<u<<" "<<v<<endl;
					if(!in[v])
						continue;
					in[v]=in[u]=0;
					pop(u);
					pop(v);
					ans+=100;
					x--;
					y--;
					break;
				}
				//cout<<ans<<" "<<x<<" "<<y<<endl;
			}
		}
	}
	//cout<<min(x,y)<<" "<<max(x,y)<<endl;
	ans+=min(x,y)*10+max(x,y)-min(x,y);
	cout<<ans<<endl;
	return 0;
}