#include <iostream>
#include <vector>
#include <queue>
#include <utility>
using namespace std;
vector<int> dy = {1, 0, -1, 0};
vector<int> dx = {0, 1, 0, -1};
int main(){
	int H, W;
	cin >> H >> W;
	vector<vector<int>> A(H + 2, vector<int>(W + 2, 0));
	for (int i = 1; i <= H; i++){
		for (int j = 1; j <= W; j++){
			cin >> A[i][j];
		}
	}
	vector<vector<bool>> used(H + 2, vector<bool>(W + 2, false));
	int ans = 0;
	for (int i = 1; i <= H; i++){
		for (int j = 1; j <= W; j++){
			if (A[i][j] == 1 && !used[i][j]){
				used[i][j] = true;
				ans++;
				queue<pair<int, int>> Q;
				Q.push(make_pair(i, j));
				while (!Q.empty()){
					int y = Q.front().first;
					int x = Q.front().second;
					Q.pop();
					for (int k = 0; k < 4; k++){
						int y2 = y + dy[i];
						int x2 = x + dx[i];
						if (A[y2][x2] == 1 && !used[y2][x2]){
							used[y2][x2] = true;
							Q.push(make_pair(y2, x2));
						}
					}
				}
			}
		}
	}
	cout << ans << endl;
}