#include <bits/stdc++.h>
#define int long long
#define mp make_pair
#define eb emplace_back
#define fi first
#define se second
using namespace std;
using cd = complex <double>;
const long long INF = 1e15;
const int mod = 998244353;//1e9 + 7;//786433;
const double Pi = acos(-1);
void Fastio()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
}
int h, w;
char g;
char a[4005][4005];
queue <pair <int, int> > BFS, Wait;
int cnt = 0;
bool Vis[4005][4005], Marked[4005][4005];
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
signed main()
{
Fastio();
cin >> h >> w;
for(int i = 1; i <= h; i++)
{
for(int j = 1; j <= w; j++)
{
cin >> a[i][j];
}
}
Wait.push(mp(1, 1));
while(Wait.empty() == false)
{
++cnt;
g = a[Wait.front().fi][Wait.front().se];
while(Wait.empty() == false)
{
BFS.push(Wait.front());
Wait.pop();
}
while(BFS.empty() == false)
{
int x = BFS.front().fi, y = BFS.front().se;
Vis[x][y] = true;
BFS.pop();
for(int i = 0; i < 4; i++)
{
int tx = x + dx[i], ty = y + dy[i];
if(!Vis[tx][ty] && a[tx][ty] == g)
{
BFS.push(mp(tx, ty));
Vis[tx][ty] = true;
}
else if(!Vis[tx][ty] && a[tx][ty] != '.' && a[tx][ty] != 0 && !Marked[tx][ty])
{
Marked[tx][ty] = true;
Wait.push(mp(tx, ty));
}
}
}
}
cout << cnt;
}
