#include <bits/stdc++.h>
using namespace std;
int sze[16000001] = {};
int par[16000001] = {};
void init (int x) {
sze[x] = 1;
par[x] = x;
}
int f(int x) {
return (par[x] == x ? x : par[x] = f(par[x]));
}
void merge (int x, int y) {
x = f(x);
y = f(y);
if (x == y) return;
if (sze[x] > sze[y]) swap(x, y);
sze[y] += sze[x];
par[x] = y;
}
int main () {
int n, m;
cin >> n >> m;
char arr[n + 1][m + 1];
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
cin >> arr[i][j];
}
}
for (int i = 1; i <= n * m; i++) init(i);
int ign[n * m + 1] = {};
for (int i = 1; i <= n * m; i++) {
int y = i%m;
if (y == 0) y = m;
int x = (i - y)/m + 1;
if (arr[x][y] == '.') {
ign[i] = 1;
continue;
}
if (x < n && arr[x + 1][y] != '.') merge(i, i + m);
if (x > 1 && arr[x - 1][y] != '.') merge(i, i - m);
if (y < m && arr[x][y + 1] != '.') merge(i, i + 1);
if (y > 1 && arr[x][y - 1] != '.') merge(i, i - 1);
}
map <int, set <char>> pp;
for (int i = 1; i <= n * m; i++) {
if (ign[i]) continue;
int y = i%m;
if (!y) y = m;
pp[f(i)].insert(arr[(i - y)/m + 1][y]);
}
int cnt = 0;
for (auto i : pp) {
cnt += i.second.size();
}
cout << cnt << '\n';
}
