#include #include #include #include #include using namespace std; struct DJSet{ vector data; void init(int n){ data.assign(n, -1); } bool unionSet(int x, int y){ x = root(x); y = root(y); if (x != y){ if (data[y] memo; int rec(int i, int p, bool b, const vector> &g, const vectorgrid, DJSet &ds){ int &r = memo[i * 2 + b]; if (r == -2)cerr << "error" << endl; if (r != -1)return r; if (grid[i / grid[0].size()][i%grid[0].size()] == '.'){ int t = 0; for (int j = 0; j < g[i].size(); j++){ if (g[i][j] != p){ t += rec(g[i][j], i, b,g, grid, ds); } } r = t; } else{ int t = 0, u = 0; for (int j = 0; j < g[i].size(); j++){ int to = g[i][j]; if (to != p) { int x = rec(to, i, false, g, grid, ds); int y = rec(to, i, true, g, grid, ds); t += max(x, y); u += y; } } r = t; if (!b){ r = max(r, u + ds.size(i)); } } return r; } int main(){ int N, M; while (~scanf("%d%d", &N, &M)){ vector grid(N + 2); grid[0] = string(M, '.'); for (int i = 0; i < M; i++){ cin >> grid[i+1]; } for (int i = 0; i < N + 2; i++){ grid[i] = "." + grid[i] + "."; } N += 2; M += 2; DJSet ds; ds.init(N*M); for (int i = 0; i < N; i++){ for (int j = 0; j < M; j++){ for (int dx = -1; dx <= 1; dx++){ for (int dy = -1; dy <= 1; dy++){ if (dx || dy){ int yy = i + dy; int xx = j + dx; if (yy == -1 || xx == -1 || yy == N || xx == M)continue; if (grid[i][j] = '.'&&abs(dx) + abs(dy) > 1)continue; if (grid[i][j] != grid[yy][xx])continue; ds.unionSet(i*M + j, yy*M+xx); } } } } } vector> g(N*M); for (int i = 0; i < N; i++){ for (int j = 0; j < M; j++){ for (int dx = -1; dx <= 1; dx++){ for (int dy = -1; dy <= 1; dy++){ if (dx || dy){ int yy = i + dy; int xx = j + dx; if (yy == -1 || xx == -1 || yy == N || xx == M)continue; if (abs(dx) + abs(dy) > 1)continue; if (grid[i][j] != grid[yy][xx]){ g[ds.root(i*M + j)].push_back(ds.root(yy*M + j)); } } } } } } for (int i = 0; i < N*M; i++){ vector &v = g[i]; sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); } memo.assign(N*M * 2, -1); int ans=rec(ds.root(N*M-1),-1,false,g,grid,ds); printf("%d\n", ans); } return 0; }