#include <bits/stdc++.h>

using namespace std;

int arr[1010][1010];
pair<int, int> pp;
set<pair<int, int>> spots;

void remover(int i, int j) {
    pp = make_pair(i, j);
    spots.erase(pp);
    arr[i][j] = 0;
    if(arr[i - 1][j] == 1 and i - 1 >= 0) {
        remover(i - 1, j);
    }
    if(arr[i + 1][j] == 1) {
        remover(i + 1, j);
    }
    if(arr[i][j + 1] == 1) {
        remover(i, j + 1);
    }
    if(arr[i][j - 1] == 1 and j - 1 >= 0) {
        remover(i, j - 1);
    }
    return;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cin >> arr[i][j];
            if(arr[i][j] == 1) {
                pp = make_pair(i, j);
                spots.insert(pp);
            }
        }
    }
    long long ans = 0;
    //cout << spots.size() << "\n";
    while(spots.size() != 0) {
        auto itr = spots.begin();
        pp = *itr;
        remover(pp.first, pp.second);
        //cout << pp.first << " " << pp.second << "\n";
        ans++;
    }
    cout << ans << "\n";
    return 0;
}