#include<bits/stdc++.h>
using namespace std;
using ll = long long;
template<class T> using vt = vector<T>;
template<class T> using vvt = vector<vt<T>>;
template<class T> using ttt = tuple<T,T>;
using tii = tuple<int,ll>;
using vi = vector<int>;
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define pb push_back
#define mt make_tuple
#define ALL(a) (a).begin(),(a).end()
#define FST first
#define SEC second
#define DEB cerr<<"!"<<endl
#define SHOW(a,b) cerr<<(a)<<" "<<(b)<<endl
#define DIV int(1e9+7)
const int INF = (INT_MAX/2);
const ll LLINF = (LLONG_MAX/2);
const double eps = 1e-8;
//const double PI = M_PI;  
inline ll pow(ll x,ll n,ll m){ll r=1;while(n>0){if((n&1)==1)r=r*x%m;x=x*x%m;n>>=1;}return r%m;}
inline ll lcm(ll d1, ll d2){return d1 / __gcd(d1, d2) * d2;}

/*Coding Space*/
bool in[3000][3000]={};
int vec[] = {1,0,-1,0,1};
int h,w;

int main(){
  cin >> h >> w;
  rep(i,h)rep(j,w) cin >> in[i][j];
  int ans = 0;
  rep(i,h)rep(j,w)if(in[i][j] == 1){
    //DEB;
    //SHOW(i,j);
    ++ans;
    queue<tii> q;
    q.push(tii{i,j});
    while(!q.empty()){
      int a,b; tie(a,b) = q.front(); q.pop();
      in[a][b] = 0;
      rep(x,4){
        int ni = a + vec[x];
        int nj = b + vec[x+1];
        //SHOW(ni,nj);
        //cerr << in[ni][nj] << endl;
        if(ni < 0 || ni >= h || nj < 0 || nj >= w)  continue;
        if(in[ni][nj] == 1)q.push(tii{ni,nj});
      }
    }
  }
  cout << ans << endl;
}