#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>
#define endl '\n'
using ll = long long;
#define pb push_back
#define eb emplace_back
#define pF first
#define pS second
#define SP << " " <<
const ll mod7 = 1e9+7, mod9= 998244353;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
char a[1112][1123];
ll n, m;
bool vis[1112][1123];
vector<ll> dx = {0, 0, 1, -1}, dy = {1, -1, 0, 0};
void dfs(ll i, ll j) {
vis[i][j] = 1;
for (int k = 0; k < 4; k++){
if (!(i+dx[k] <= n && i + dx[k] > 0 && j + dy[k] <= m && j + dy[k] > 0) || vis[i+dx[k]][j+dy[k]] || a[i+dx[k]][j+dy[k]] != a[i][j]) continue;
dfs(i+dx[k], j+dy[k]);
}
}
int main() {
//ios::sync_with_stdio(0); cout.tie(0); cin.tie(0);
cin>>n>>m;
for (int i = 1; i<=n; i++)
for (int j=1; j<=m; j++)
cin>>a[i][j];
ll cnt = 0;
char c = a[1][1];
for (int i=1; i<=n; i++)
for (int j = 1; j <=n; j++)
if (!vis[i][j]) dfs(i, j), cnt++;
cout << cnt << endl;
}
