#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int h, w;
cin >> h >> w;
vector<string> arr(h);
for (int i = 0; i < h; ++i) {
cin >> arr[i];
}
deque<pair<int, int>> stk;
char cur_char = arr[0][0];
stk.push_front({0, 0});
int cnt = 1;
while(!stk.empty()) {
auto [x, y] = stk.front();
stk.pop_front();
if (arr[x][y] == '.') {
continue;
}
if (arr[x][y] != cur_char) {
++cnt;
cur_char = arr[x][y];
}
arr[x][y] = '.';
int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};
for (int i = 0; i < 4; ++i) {
int nx = x + dx[i];
int ny = y + dy[i];
if (nx >= h || ny >= w || nx < 0 || ny < 0 || arr[nx][ny] == '.') {
continue;
} else if (arr[nx][ny] == cur_char) {
stk.push_front({nx, ny});
} else {
stk.push_back({nx, ny});
}
}
}
cout << cnt << endl;
return 0;
}
