#include "bits/stdc++.h"

using namespace std;

using ll = long long;
using ld = long double;

const int INF = (1 << 30) - 1;
const ll INF64 = ((ll)1 << 62) - 1;
const double PI = 3.1415926535897932384626433832795;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { -1, 0, 1, 0 };

int h, w;
vector<vector<int>> a;

void bfs(int sy, int sx) {
	queue<pair<int, int>> que;
	que.emplace(sy, sx);
	a[sy][sx] = 0;

	while (!que.empty()) {
		pair<int, int> now = que.front(); que.pop();
		for (int i = 0; i < 4; i++) {
			int ny = now.first + dy[i];
			int nx = now.second + dx[i];

			if (nx < 0 || w <= nx || ny < 0 || h <= ny || a[ny][nx] == 0) {
				continue;
			}

			a[ny][nx] = 0;
			que.emplace(ny, nx);
		}
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> h >> w;

	a.resize(h, vector<int>(w));
	for (int i = 0; i < h; i++) {
		for (int j = 0; j < w; j++) {
			cin >> a[i][j];
		}
	}

	int ans = 0;
	for (int i = 0; i < h; i++) {
		for (int j = 0; j < w; j++) {
			if (a[i][j] != 1) {
				continue;
			}

			bfs(i, j);
			ans++;
		}
	}

	cout << ans << endl;
	return 0;
}