#include <iostream>
#include <stack>

using namespace std;

int main()
{

	int ans = 0;

	int h, w;
	cin >> h >> w;
	
	int masu[h][w];
	for(int i=0; i<h; ++i)
		for(int j=0; j<w; ++j)
			cin >> masu[i][j];
	
	stack<int> stkH;
	stack<int> stkW;
	

	for(int i=0; i<h; ++i)
		for(int j=0; j<w; ++j)
			if(masu[i][j]){
				++ans;
				masu[i][j] = 0;
				int a = i;
				int b = j;
				while(1){
					if(b + 1 < w && masu[a][b+1]){
						masu[a][b+1] = 0;
						stkH.push(a);
						stkW.push(b+1);
					}
					if(b - 1 >= 0 && masu[a][b-1]){
						masu[a][b-1] = 0;
						stkH.push(a);
						stkW.push(b-1);
					}
					if(a - 1 >= 0 && masu[a - 1][b]){
						masu[a - 1][b] = 0;
						stkH.push(a-1);
						stkW.push(b);
					}
					if(a + 1 < h && masu[a + 1][b]){
						masu[a + 1][b] = 0;
						stkH.push(a+1);
						stkW.push(b);
					}
					if(!stkH.empty()){
						a = stkH.top();
						b = stkW.top();
						stkH.pop();
						stkW.pop();
					}
					else
						break;
					
				}
			}

	cout << ans << endl;

	return 0;
}