#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <unordered_set>
#include <set>
#include <unordered_map>
#include <map>
#include <utility>
#include <stack>
#include <math.h>
#include <queue>
#include <cstring>
#include <algorithm>
#include <iomanip>
#include <numeric>
using namespace std;
#define int long long
#define INF (int)1e18
// #define endl '\n'
const int mod = 1000 * 1000 * 1000 + 7;
const int N = 4005;
#define f first
#define s second
// mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
char a[N][N];
queue<pair<int,int> > pq , nq;
int vis[N][N];
int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
void Solve() {
int n , m; cin>>n>>m;
for(int i = 1 ;i<= n ; i++){
for(int j = 1; j<= m ; j++){
cin>>a[i][j];
}
}
int cnt = 0;
char c ;
vis[1][1] = true;
pq.push({1,1});
while (!pq.empty()){
cnt++;
c = a[pq.front().first][pq.front().second];
while (!pq.empty())nq.push(pq.front()) , pq.pop();
while (!nq.empty()){
auto v = nq.front();
// cout << v.first << " " << v.second << endl;
nq.pop();
for (int i = 0; i < 4; ++i) {
int nx = v.first+dx[i], ny = v.second + dy[i];
if (nx<1 || ny<1 ||nx>n ||ny>m || a[nx][ny]=='.' || vis[nx][ny]){continue;}
vis[nx][ny] = true;
// cout << nx << " " << ny << " " << vis[nx][ny] << endl;
if (a[nx][ny]==c){
nq.push({nx,ny});
}
else{
pq.push({nx,ny});
}
// }
}
}
}
cout<<cnt<<endl;
}
int32_t main() {
// auto begin = std::chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(false);
cin.tie(0);
// #ifndef ONLINE_JUDGE
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
// #endif
int t = 1;
// cin >> t;
for (int i = 1; i <= t; i++) {
//cout << "Case #" << i << ": ";
Solve();
}
// auto end = std::chrono::high_resolution_clock::now();
// auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
// cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
return 0;
}
