#include<bits/stdc++.h>
using namespace std;
#define ALL(x) begin(x),end(x)
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 998244353
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}
template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}

struct UnionFind{
    private:
    vector<int> par,siz;

    public:
    int con;
    UnionFind(int n):par(n),siz(n,1),con(n){
        iota(begin(par),end(par),0);
    }
    int root(int x){
        return (par[x]==x?x:(par[x]=root(par[x])));
    }
    bool sameroot(int x,int y){
        return root(x)==root(y);
    }
    bool unite(int x,int y){
        x=root(x);y=root(y);
        if(x==y) return false;
        if(siz[x]<siz[y])swap(x,y);
        siz[x]+=siz[y];
        par[y]=x;
        con--;
        return true;
    }
    int size(int x){
        return siz[root(x)];
    }
};

signed main(){
    int h,w;cin>>h>>w;
    vector<vector<int>> v(h,vector<int>(w));
    cin>>v;

    UnionFind uf(h*w);
    rep(i,h){
        rep(j,w)if(v[i][j]){
            rep(k,4){
                int ni=i+dx[k],nj=j+dy[k];
                if(0<=ni and ni<h and 0<=nj and nj<w and v[ni][nj]) uf.unite(i*w+j,ni*w+nj);
            }
        }
    }

    int res=0;
    rep(i,h)rep(j,w)if(v[i][j] and uf.root(i*w+j)==i*w+j) res++;
    cout<<res<<endl;
    return 0;
}