#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;

int H, W;
int dxy[5] = {-1, 0, 1, 0, -1};
bool v[3005][3005];
int ans;
void dfs(int y, int x)
{
    if (v[y][x] == false)
        return;
    v[y][x] = 0;
    for (int i = 1; i < 5; ++i)
    {
        int ny = y + dxy[i], nx = x + dxy[i - 1];
        if (ny >= 0 && nx >= 0 && ny < H && nx < W && v[ny][nx] != false)
        {
            dfs(ny, nx);
        }
    }
    return;
}
int main(void)
{
    cin >> H >> W;
    for (int i = 0; i < H; ++i)
    {
        for (int j = 0; j < W; ++j)
        {
            int a;
            cin >> a;
            if (a == 1)
                v[i][j] = true;
            else
                v[i][j] = false;
        }
    }
    for (int i = 0; i < H; ++i)
    {
        for (int j = 0; j < W; ++j)
        {
            if (v[i][j])
            {
                dfs(i, j);
                ans++;
            }
        }
    }
    cout << ans << endl;
    return 0;
}