/*
* author : Apiram
* created: 29.06.2023 01:16:40
*/
#include<bits/stdc++.h>
using namespace std;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n,m;cin>>n>>m;
vector<int>dx = {-1,1,0,0};
vector<int>dy = {0,0,-1,1};
vector<string>arr(n);
for (int i = 0;i<n;++i){
cin>>arr[i];
}
deque<pair<int,int>>q;
q.push_back({0,0});
vector<vector<bool>>visited(n,vector<bool>(m,0));
visited[0][0] = 1;
int ans = 1;
char cur = arr[0][0];
while(!q.empty()){
auto u = q.back();
q.pop_back();
if (arr[u.first][u.second]!=cur){
cur = arr[u.first][u.second];
++ans;
}
for (int i = 0;i<4;++i){
int nx = u.first + dx[i];
int ny = u.second + dy[i];
if (nx < 0 || ny < 0 || nx >= n || ny >= m || arr[nx][ny] == '.' || visited[nx][ny])continue;
visited[nx][ny] = true;
if (arr[nx][ny] == arr[u.first][u.second]){
q.push_back({nx,ny});
}
else{
q.push_front({nx,ny});
}
}
}
cout<<ans<<'\n';
return 0;
}
