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

public class Main {
    static boolean[][] field;
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] first = br.readLine().split(" ", 2);
        int h = Integer.parseInt(first[0]);
        int w = Integer.parseInt(first[1]);
        field = new boolean[h + 2][w + 2];
        for (int i = 1; i <= h; i++) {
            String[] line = br.readLine().split(" ", w);
            for (int j = 1; j <= w; j++) {
                field[i][j] = line[j - 1].charAt(0) == '1';
            }
        }
        int count = 0;
        for (int i = 1; i <= h; i++) {
            for (int j = 1; j <= w; j++) {
                if (field[i][j]) {
                    setCell(i, j);
                    count++;
                }
            }
        }
        System.out.println(count);
    }
    
    static void setCell(int hh, int ww) {
        if (!field[hh][ww]) {
            return;
        }
        field[hh][ww] = false;
        setCell(hh - 1, ww);
        setCell(hh + 1, ww);
        setCell(hh, ww - 1);
        setCell(hh, ww + 1);
    }
}