#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

vector<vector<bool>> field;
vector<bool> x;

void dfs(int y, int x){
    field[y][x] = 0;
    if (field[y+1][x])
        dfs(y+1, x);
    if (field[y-1][x])
        dfs(y-1, x);
    if (field[y][x+1])
        dfs(y, x+1);
    if (field[y][x-1])
        dfs(y, x-1);
    return;
}

int main(){
    int h, w, k, counter;
    cin >> h >> w;
    counter = 0;
    
    for (int i = 0; i < w + 2; i++)
        x.push_back(0);
    field.push_back(x);
    x.clear();
    
    for (int i = 0; i < h; i++){
        x.push_back(0);
        for (int j = 0; j < w; j++){
            cin >> k;
            x.push_back(k);
        }
        x.push_back(0);
        field.push_back(x);
        x.clear();
    }

    for (int i = 0; i < w + 2; i++)
        x.push_back(0);
    field.push_back(x);
    
    // for (auto v : field){
    //     for (auto w : v)
    //         cout << w;
    //     cout << endl;
    // }
    
    for (int i = 0; i < h; i++){
        for (int j = 0; j < w; j++){
            if (field[i+1][j+1]){
                dfs(i+1, j+1);
                counter++;
            }
        }
    }
    
    // for (auto v : field){
    //     for (auto w : v)
    //         cout << w;
    //     cout << endl;
    // }
    
    cout << counter << endl;
    return 0;

}