dfs на поле

////https://informatics.msk.ru/mod/statements/view.php?id=256&chapterid=652#1
#include <iostream>
#include <set>
#include <vector>
#include <deque>

#define se second
#define fi first
#define mp make_pair
#define pb push_back

using namespace std;

int n, m;
vector <string> g;
vector<vector<bool>> used;

vector<pair<int, int>> nei = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};

bool valid(int x, int y) {
    return (0 <= min(x, y) && x < n && y < m && g[x][y] != '.');
}

void dfs(pair<int, int> h) {
    used[h.fi][h.se] = true;
    for (auto e : nei) {
        int x = h.fi + e.fi;
        int y = h.se + e.se;
        if (valid(x, y) && !used[x][y]){
            dfs({x, y});
        }
    }
}

int main() {
    cin >> n >> m;
    g.resize(n);
    for (auto& e : g) cin >> e;
    used.assign(n, vector<bool>(m, false));
    int answ = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (g[i][j] != '.' && !used[i][j]) {
                answ++;
                dfs({i, j});
            }
        }
    }
    cout << answ;
    return 0;
}