#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
using ll = long long;
using vll = vector<ll>;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<ll>>;
const ll inf = 1e16;
const ll md = 1000000007;

int a[3005][3005];
int h,w;

void dfs(int i,int j){
  a[i][j]=0;
  rep(ij,2) rep(pm,2){
    int ni=i+(pm*2-1)*ij;
    int nj=j+(pm*2-1)*(1-ij);
    if(ni<0 || nj<0 || ni>=h || nj>=w) continue;
    if(a[ni][nj]==0) continue;
    dfs(ni,nj);
  }
}

int main() {
  cin>>h>>w;
  rep(i,h) rep(j,w) cin>>a[i][j];
  int ans=0;
  rep(i,h) rep(j,w){
    if(a[i][j]==0) continue;
    ans++;
    dfs(i,j);
  }
  cout<<ans<<endl;
  return 0;
}