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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int h = sc.nextInt();
        int w = sc.nextInt();
        boolean[][] isWater = new boolean[h][w];
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                isWater[i][j] = (sc.nextInt() == 1);
            }
        }
        ArrayDeque<Integer> current = new ArrayDeque<>();
        int ans = 0;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (!isWater[i][j]) {
                    continue;
                }
                ans++;
                current.add(i * w + j);
                while (current.size() > 0) {
                    int x = current.poll();
                    int r = x / w;
                    int c = x % w;
                    if (!isWater[r][c]) {
                        continue;
                    }
                    isWater[r][c] = false;
                    if (r > 0) {
                        current.add(x - w);
                    }
                    if (r < h - 1) {
                        current.add(x + w);
                    }
                    if (c > 0) {
                        current.add(x - 1);
                    }
                    if (c < w - 1) {
                        current.add(x + 1);
                    }
                }
            }
        }
        System.out.println(ans);
    }
    
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}