#include<iostream>
#include<vector>
#include<string>

using namespace std;

struct Union_Find {

	std::vector<int> parent;
	std::vector<int> rank;
	int N;

	Union_Find(int n) {
		N = n;
		parent = std::vector<int>(N, -1);
		rank = std::vector<int>(N, 0);
	}

	int find(int x) {
		if (parent[x] < 0) return x;
		return parent[x] = find(parent[x]);
	}

	int size(int x) {
		return -parent[find(x)];
	}

	void unite(int x, int y) {
		x = find(x);
		y = find(y);

		if (x == y) return;
		if (parent[x] > parent[y]) std::swap(x, y);
		parent[x] += parent[y];
		parent[y] = x;
		return;
	}

	bool same(int x, int y) {
		return find(x) == find(y);
	}

	int group_count() {
		int K = 0;
		for (int i = 0; i < N; i++) {
			if (parent[i] < 0) K++;
		}
		return K;
	}

	std::vector<int> members(int x) {
		std::vector<int> v(0);

		int r = find(x);
		for (int i = 0; i < N; i++) {
			if (find(i) == r) v.push_back(i);
		}
		return v;
	}
};

int main() {
	int H, W;
	int K = 0;
	int a, b, c;

	cin >> H >> W;

	vector<vector<int>> S(H, vector<int>(W));
	vector<vector<int>> T(H, vector<int>(W, -1));

	for (int y = 0; y < H; y++) {
		for (int x = 0; x < W; x++) {
			cin >> S.at(y).at(x);

			if (S.at(y).at(x) == 1) {
				T.at(y).at(x) = K;
				K++;
			}
		}
	}

	Union_Find U(K);
	for (int y = 0; y < H; y++) {
		for (int x = 0; x < W; x++) {
			if (S.at(y).at(x) == 1) {
				a = T.at(y).at(x);
				if (y < H - 1 && S.at(y + 1).at(x) == 1) {
					b = T.at(y + 1).at(x);
					U.unite(a, b);
				}

				if (x < W - 1 && S.at(y).at(x + 1) == 1) {
					c = T.at(y).at(x + 1);
					U.unite(a, c);
				}
			}
		}
	}

	cout << U.group_count() << endl;
	return 1;
}