import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;

public class Main{
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		PrintWriter out=new PrintWriter(System.out);
		String[] hw=scanner.nextLine().split(" ");
		int h=Integer.parseInt(hw[0]);
		int w=Integer.parseInt(hw[1]);
		boolean[][] a=new boolean[h][w];
		int cnt=0;
		for(int i=0; i<h; i++) {
			for(int j=0; j<w; j++) {
				a[i][j]=Boolean.parseBoolean(scanner.next());
				if(a[i][j]) cnt++;
			}
		}
		UnionFind uf=new UnionFind(h*w);
		for(int i=0; i<h; i++) {
			for(int j=0; j<w; j++) {
				if(!a[i][j]) continue;
				int x=i*w+j;
				if(i+1<h && a[i+1][j]) {
					if(uf.unite(x, (i+1)*w+j)) cnt--;
				}
				if(j+1<w && a[i][j+1]) {
					if(uf.unite(x,  i*w+j+1)) cnt--;
				}
			}
		}
		out.println(cnt);
		out.close();
		scanner.close();
	}
}
class UnionFind{
	int n;
	int[] par;
	int cmp;
	public UnionFind(int n) {
		this.n=n;
		this.par=new int[n];
		Arrays.fill(this.par, -1);
		this.cmp=n;
	}
	public int find(int x) {
		if(par[x]<0) return x;
		return par[x]=find(par[x]);
	}
	public boolean unite(int x, int y) {
		x=find(x);
		y=find(y);
		if(x==y) {
			return false;
		}
		cmp--;
		if(par[x]>par[y]) {
			int tmp=x;
			x=y;
			y=tmp;
		}
		par[x]+=par[y];
		par[y]=x;
		return true;
	}
	public boolean same(int x, int y) {
		return find(x)==find(y);
	}
}