#include <iostream>
#include <vector>
#include <queue>

using namespace std;

int main() {
    int H, W;
    cin >> H >> W;

    vector<vector<int>> A(H, vector<int>(W));
    for (int h = 0; h < H; ++h) {
        for (int w = 0; w < W; ++w) {
            cin >> A[h][w];
        }
    }

    int ans = 0;
    for (int h = 0; h < H; ++h) {
        for (int w = 0; w < W; ++w) {
            if (A[h][w]) {
                queue<pair<int, int>> q;
                q.push({h, w});
                A[h][w] = 0;

                while (!q.empty()) {
                    int hh = q.front().first;
                    int ww = q.front().second;
                    q.pop();

                    vector<pair<int, int>> directions = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
                    for (const auto& dir : directions) {
                        int dh = dir.first;
                        int dw = dir.second;
                        if (0 <= hh + dh && hh + dh < H && 0 <= ww + dw && ww + dw < W && A[hh + dh][ww + dw]) {
                            A[hh + dh][ww + dw] = 0;
                            q.push({hh + dh, ww + dw});
                        }
                    }
                }
                ans++;
            }
        }
    }

    cout << ans << endl;

    return 0;
}