#include <bits/stdc++.h>
using namespace std;
int di[4] = {0, 1, 0, -1};
int dj[4] = {1, 0, -1, 0};
int main(void){
    int h, w;
    cin >> h >> w;
    vector<int> A(h * w);
    for(int i = 0; i < h * w; i++) cin >> A[i];
    int ans = 0;
    for(int i = 0; i < h; i++){
        for(int j = 0; j < w; j++){
            if (A[i * w + j] == 0) continue;
            A[i * w + j] = 0;
            ans++;
            queue<int> que;
            que.push(i * w + j);
            while(!que.empty()){
                int tmp = que.front();
                que.pop();
                int ii = tmp / w;
                int jj = tmp - ii * w;
                for(int k = 0; k < 4; k++){
                    int ni = ii + di[k];
                    int nj = jj + dj[k];
                    if(ni == -1 || ni == h || nj == -1 || nj == w) continue;
                    if(A[ni * w + nj] == 0) continue;
                    A[ni * w + nj] = 0;
                    que.push(ni * w + nj);
                }
            }
        }
    }
    cout << ans << "\n";
}