#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)


int h, w;
int a[3010][3010];
const int dy[] = {1, 0, -1, 0}, dx[] = {0, 1, 0, -1};

int main(int argc, char const *argv[])
{
	cin >> h >> w;
	rep(i, h)rep(j, w) cin >> a[i][j];

	int ans = 0;

	rep(i, h)rep(j, w) {
		if (a[i][j] == 0) continue;

		queue<pair<int, int>> que;
		que.push(make_pair(i, j));
		a[i][j] = 0;
		ans++;

		while(!que.empty()) {
			int y = que.front().first, x = que.front().second;
			que.pop();
			rep(k, 4) {
				int ny = y + dy[k], nx = x + dx[k];
				if (!(0 <= ny && ny < h && 0 <= nx && nx < w)) continue;
				if (a[ny][nx] == 1) {
					a[ny][nx] = 0;
					que.push(make_pair(ny, nx));
				}
			}
		}

	}

	printf("%d\n", ans);
	return 0;
}