#include <bits/stdc++.h>
using namespace std;
/*
---===ASCII help===---
'0' -> 48 '9' -> 57
'A' -> 65 'Z' -> 90
'a' -> 97 'z' -> 122
*/
const long long mod = 1e9 + 7;
void solve() {
int n, m; cin >> n >> m;
vector<string> matrix(n);
for (string& s : matrix) cin >> s;
vector<vector<bool>> visited(n, vector<bool>(m, false));
deque<pair<int, int>> q;
q.push_back({0, 0});
visited[0][0] = true;
int ans = 0;
char c = '#';
while (!q.empty()) {
auto [x, y] = q.front();
if (matrix[x][y] != c) ans++;
c = matrix[x][y];
q.pop_front();
vector<pair<int, int>> directions = {{x + 1, y}, {x - 1, y}, {x, y + 1}, {x, y - 1}};
for (auto [a, b] : directions) {
if (a < 0 || b < 0 || a >= n || b >= m) continue;
if (visited[a][b] || matrix[a][b] == '.') continue;
visited[a][b] = true;
if (matrix[a][b] == matrix[x][y]) q.push_front({a, b});
else q.push_back({a, b});
}
}
cout << ans << "\n";
}
int main() {
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
