import java.util.*;
import java.io.*;

public class Main {
    
    private static int[] dy = {0,1,0,-1};
    private static int[] dx = {1,0,-1,0};
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    
    public static void main(String[] args) throws Exception {

    	int[] h_w = readIntArray();
        int h = h_w[0];
        int w = h_w[1];
        
        boolean[][] field = new boolean[h][w];
        for(int i = 0 ; i < h ; i++){
            String[] terrains = br.readLine().split(" ");
            for(int j = 0 ;  j < w ; j++){
                if(terrains[j].equals("1")){
                    field[i][j] = true;
                }
            }
        }
            
        int ans = 0;
        for(int i = 0 ; i < h ; i++){
            for(int j = 0 ; j < w ; j++){
                    
                if(field[i][j]){
                    field = bfs(field , i , j , h , w);
                    ans++;
                }
                    
            }
        }
            
        System.out.println(ans);
		
    }
    
    private static boolean[][] bfs(boolean[][] field , int currentH , int currentW , int h , int w){
        
        ArrayDeque<Pair> todo = new ArrayDeque<>();
        //Pair p = new Pair(currentH , currentW);
        todo.addLast(new Pair(currentH , currentW));
        field[currentH][currentW] = false;
        
        while(todo.size() > 0){
            
            Pair p = todo.pollFirst();
            currentH = p.getY();
            currentW = p.getX();
  
            for(int i = 0 ; i < 4 ; i++){
                
                int nextH = currentH + dy[i];
                int nextW = currentW + dx[i];
                
                if(nextH >= 0 && nextH < h && nextW >= 0 && nextW < w){
                    if(field[nextH][nextW]){
                        todo.addLast(new Pair(nextH , nextW));
                        field[nextH][nextW] = false;
                    }
                }
                
            }

        }
        
        return field;
                
    }
    
    private static int[] readIntArray() throws Exception{
        
		int[] intArray = Arrays.stream(br.readLine().split(" "))
							.mapToInt(Integer::parseInt).toArray();

		return intArray;

	}

}

class Pair{
    
    int y , x;
    
    public Pair(int y  , int x){
        this.y = y;
        this.x = x;
    }
    
    public int getY(){
        return y;
    }
    
    public int getX(){
        return x;
    }
    
}