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 {

        try {

    		int[] h_w = readIntArray();
            int h = h_w[0];
            int w = h_w[1];
            
            int[][] field = new int[h][w];
            for(int i = 0 ; i < h ; i++){
                
                int[] terrains = readIntArray();
                field[i] = terrains;
                
            }
            
            boolean[][] seen = new boolean[h][w];
            int ans = 0;
            for(int i = 0 ; i < h ; i++){
                for(int j = 0 ; j < w ; j++){
                    
                    int currentH = i;
                    int currentW = j;
                    if(seen[currentH][currentW] || field[currentH][currentW] == 0){
                        continue;
                    }
                    
                    seen = bfs(field , seen , currentH , currentW , h , w);
                    ans++;
                    
                }
            }
            
            System.out.println(ans);

		} catch (Exception e) {

       
		}
		
    }
    
    private static boolean[][] bfs(int[][] field , boolean[][] seen , int currentH , int currentW , int h , int w){
     
        LinkedList<int[]> todo = new LinkedList<>();
        int[] h_w = {currentH , currentW};
        todo.add(h_w);
        
        while(!todo.isEmpty()){
            
            int[] currentH_W = todo.pop();
            currentH = currentH_W[0];
            currentW = currentH_W[1];
            
            seen[currentH][currentW] = true;
            
            for(int i = 0 ; i < 4 ; i++){
                
                int nextH = currentH + dy[i];
                int nextW = currentW + dx[i];
                
                if (nextH < 0 || nextW < 0 || nextH >= h || nextW >= w) {
					continue;
                }
                if(seen[nextH][nextW] || field[nextH][nextW] == 0){
                    continue;
                }
                
                int[] nextH_W = new int[2];
                nextH_W[0] = nextH;
                nextH_W[1] = nextW;
                todo.add(nextH_W);
                
            }

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

		return intArray;

	}

}