import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.NoSuchElementException;
import java.util.Queue;

public class Main{
	public static void main(String[] args) {
		//Scanner scanner=new Scanner(System.in);
		FastScanner scanner=new FastScanner();
		PrintWriter out=new PrintWriter(System.out);
		int h=scanner.nextInt();
		int w=scanner.nextInt();
		int[][] a=new int[h][w];
		boolean[][] used=new boolean[h][w];
		for(int i=0; i<h; i++) {
			for(int j=0; j<w; j++) {
				a[i][j]=scanner.nextInt();
			}
		}
		int[] dx= {1, -1, 0, 0};
		int[] dy= {0, 0, 1, -1};
		Queue<Integer> que=new ArrayDeque<>();
		int cnt=0;
		for(int i=0; i<h; i++) {
			for(int j=0; j<w; j++) {
				if(a[i][j]==0 || used[i][j]) continue;
				cnt++;
				que.offer(i*w+j);
				used[i][j]=true;
				while(que.size()>0) {
					int xy=que.poll();
					int x=xy/w;
					int y=xy%w;
					for(int k=0; k<4; k++) {
						int x1=x+dx[k];
						int y1=y+dy[k];
						if(x1<0 || x1>=h || y1<0 || y1>=w || a[x1][y1]==0 || used[x1][y1]) continue;
						que.offer(x1*w+y1);
						used[x1][y1]=true;
					}
				}
			}
		}
		out.println(cnt);
		out.close();
		//scanner.close();
	}
}
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}