#include<bits/stdc++.h>
#define f first
#define s second
using namespace std;
typedef long long ll;
int main(){
ll h,w; cin >> h >> w;
vector<vector<char>> mp(h, vector<char>(w));
for(ll i=0; i<h; i++)
for(ll j=0; j<w; j++)
cin >> mp[i][j];
deque<pair<ll,ll>> d;
d.push_back({0,0});
vector<vector<bool>> mark(h, vector<bool>(w, false));
mark[0][0] = true;
char tmp = mp[0][0];
ll ans = 1;
while(!d.empty()){
auto v = d.back();
d.pop_back();
auto cv = mp[v.f][v.s];
if(cv != tmp){
tmp = cv;
ans++;
}
if(v.f < h-1 && !mark[v.f+1][v.s]){
mark[v.f+1][v.s] = true;
if(mp[v.f+1][v.s] == cv) d.push_back({v.f+1, v.s});
else if(mp[v.f+1][v.s] != '.') d.push_front({v.f+1, v.s});
}
if(v.s < w-1 && !mark[v.f][v.s+1]){
mark[v.f][v.s+1] = true;
if(mp[v.f][v.s+1] == cv) d.push_back({v.f, v.s+1});
else if(mp[v.f][v.s+1] != '.') d.push_front({v.f, v.s+1});
}
if(v.f > 0 && !mark[v.f-1][v.s]){
mark[v.f-1][v.s] = true;
if(mp[v.f-1][v.s] == cv) d.push_back({v.f-1, v.s});
else if(mp[v.f-1][v.s] != '.') d.push_front({v.f-1, v.s});
}
if(v.s > 0 && !mark[v.f][v.s-1]){
mark[v.f][v.s-1] = true;
if(mp[v.f][v.s-1] == cv) d.push_back({v.f, v.s-1});
else if(mp[v.f][v.s-1] != '.') d.push_front({v.f, v.s-1});
}
}
cout << ans << endl;
return 0;
}
