#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int h, w;
vector<string> grid;
vector<vector<bool>> vis;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen("input.in", "r", stdin);
cin >> h >> w;
grid = vector<string>(h);
vis = vector<vector<bool>>(h, vector<bool>(w, false));
for(int i=0; i<h; i++){
cin >> grid[i];
}
//bfs tree with connected components
//ans is depth of the tree
//can treat as edges with 0 weight to same component
//1 weight to edge to diff component
//use a kind of floodfill with bfs for the edges
deque<pair<int, int>> dq; dq.push_front({0,0});
char type = grid[0][0]; vis[0][0] = true;
int ans = 1;
while(!dq.empty()){
//floodfill bfs
pair<int, int> cur = dq.front(); dq.pop_front();
if(grid[cur.first][cur.second] != type){
ans++;
type = grid[cur.first][cur.second];
}
// cout << "CHECK" << endl;
for(int i=cur.first-1; i<=cur.first+1; i++){
if(i<0 || i>=h) continue;
// cout << "cHECKPINTS" << endl;
for(int j=cur.second-1; j<=cur.second+1; j++){
if(j<0 || j>=w) continue;
// cout << "testing " << i << " " << j << " with type " << grid[i][j] << endl;
if(vis[i][j] == true || grid[i][j] == '.' || abs((cur.first + cur.second) - (i+j)) != 1){
// cout << vis[i][j] << " " << grid[i][j] << " " << abs((cur.first+cur.second) - (i+j)) << endl;
continue;
}
else if(grid[i][j] != type){
dq.push_back({i, j});
// cout << "pushing to back" << endl;
}
else{
dq.push_front({i,j});
// cout << "pushing to front" << endl;
}
vis[i][j] = true;
}
}
}
cout << ans << endl;
}
