#include <bits/stdc++.h>
using namespace std;
char cmap[4000][4000];
bool seen[4000][4000];
int n, m;
char currChar;
int changeCount = 1;
int dx[] = {0, 1, 0, -1};
int dy[] = {-1, 0, 1, 0};
void flood_fill(pair<int, int> curr, deque<pair<int, int>>& q) {
int y = curr.first, x = curr.second;
if (seen[y][x])
return;
seen[y][x] = true;
for (int i = 0; i < 4; i++) {
int nextY = y + dy[i];
int nextX = x + dx[i];
if (nextY < 0 || nextY > n - 1)
continue;
if (nextX < 0 || nextX > m - 1)
continue;
if (seen[nextY][nextX])
continue;
char c = cmap[nextY][nextX];
if (c == '.')
continue;
if (c != currChar) {
q.push_back(make_pair(nextY, nextX));
continue;
}
flood_fill(make_pair(nextY, nextX), q);
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
cin >> cmap[i][j];
}
}
currChar = cmap[0][0];
pair<int, int> curr;
deque<pair<int, int>> q;
q.push_back({0, 0});
while (!q.empty()) {
curr = q.front();
if (seen[curr.first][curr.second]) {
q.pop_front();
continue;
}
if (cmap[curr.first][curr.second] != currChar) {
changeCount++;
currChar = cmap[curr.first][curr.second];
}
flood_fill(curr, q);
q.pop_front();
}
cout << changeCount << "\n";
}
