#include "bits/stdc++.h"
#include <type_traits>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
// ============ Macros starts here ============
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) {++recur_depth; auto x_=x; --recur_depth; cerr<<string(recur_depth, '\t')<<"\e{91m"<<__func__<<":"<<__LINE__<<"\t"<<#x<<" = "<<x_<<"\e{39m"<<endl;}
#else
#define dbg(x)
#endif // DEBUG
template<typename Ostream, typename Cont>
typename enable_if<is_same<Ostream, ostream>::value, Ostream&>::type operator<<(Ostream& os, const Cont& v) {
os << "{";
for (auto& x : v) { os << x << ", "; }
return os << "}";
}
template<typename Ostream, typename ...Ts>
Ostream& operator<<(Ostream& os, const pair<Ts...>& p) {
return os << "{" << p.first << ", " << p.second << "}";
}
#define readFast \
ios_base::sync_with_stdio(false); \
cin.tie(0); \
cout.tie(0);
#ifdef LOCAL
#define read() ifstream fin("date.in.txt")
#else
#define read() readFast
#endif // LOCAL
// ============ Macros ends here ============
#define fin cin
#define ll long long
#define sz(x) (int)(x).size()
#define all(v) v.begin(), v.end()
#define output(x) (((int)(x) && cout << "YES\n") || cout << "NO\n")
#define LSB(x) (x & (-x))
#define test cout << "WORKS\n";
const int N = 1e5 + 15;
const int MOD = 1e9 + 7;
int dl[] = { 0, 1, 0, -1 };
int dc[] = { 1, 0, -1, 0 };
int main() {
read();
int n, m;
fin >> n >> m;
vector<vector<char>> a(n + 2, vector<char>(m + 2, '.'));
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
fin >> a[i][j];
}
}
vector<vector<bool>> vis(n + 2, vector<bool>(m + 2, false));
deque<pair<int, int>> deq;
vector<char> history;
deq.push_front({ 1,1 });
vis[1][1] = 1;
history.push_back(a[1][1]);
while (!deq.empty()) {
int x = deq.front().first;
int y = deq.front().second;
deq.pop_front();
if (a[x][y] != history.back()) {
history.push_back(a[x][y]);
}
for (int i = 0; i < 4; ++i) {
int new_x = x + dl[i];
int new_y = y + dc[i];
if (vis[new_x][new_y]) continue;
if (a[new_x][new_y] == a[x][y]) {
deq.push_front({ new_x, new_y });
} else if (a[new_x][new_y] != '.') {
deq.push_back({ new_x, new_y });
}
vis[new_x][new_y] = 1;
}
}
cout << sz(history) << '\n';
return 0;
} /*stuff you should look for !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
* test the solution with the given example
* int overflow, array bounds, matrix bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
~Benq~*/
