/*
    Author:zeke
    
    pass System Test!
    GET AC!!
*/
#include <iostream>
#include <queue>
#include <vector>
#include <iostream>
#include <vector>
#include <string>
#include <cassert>
#include <algorithm>
#include <functional>
#include <cmath>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <map>
#include <iomanip>
#include <utility>
#include <stack>
using ll = long long;
using ld = long double;
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(), (x).end()
#define rep3(var, min, max) for (ll(var) = (min); (var) < (max); ++(var))
#define repi3(var, min, max) for (ll(var) = (max)-1; (var) + 1 > (min); --(var))
#define Mp(a, b) make_pair((a), (b))
#define F first
#define S second
#define Icin(s) \
    ll(s);      \
    cin >> (s);
#define Scin(s) \
    ll(s);      \
    cin >> (s);
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef vector<V> VV;
typedef vector<P> VP;
ll mod = 1e9 + 7;
ll INF = 1e18;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int h, w;
    cin >> h >> w;
    vector<vector<int>> vec(h, vector<int>(w));
    rep(i, h) rep(j, w) cin >> vec[i][j];
    int dx[] = {-1, 0, 1, 0};
    int dy[] = {0, 1, 0, -1};
    ll res = 0;
    queue<pair<int, int>> q;
    vector<vector<bool>> have(h, vector<bool>(w,false));
    rep(i,h){
        rep(j,w){
            if(!have[i][j]&&vec[i][j]==1){
                res++;
                q.push({i, j});
                while(!q.empty()){
                  //  cout<<q.size()<<endl;
                    P p = q.front();
                    q.pop();
                    
                    int X=p.S;
                    int Y = p.F;
                 //   cout<<Y<<" "<<X<<endl;
                    have[Y][X]=1;
                    rep(k,4){
                        if (X + dx[k] >= 0 && X + dx[k] < w&&Y+dy[k]>=0&&Y+dy[k]<h){
                            if(!have[Y+dy[k]][X+dx[k]]&&vec[Y+dy[k]][X+dx[k]]==1){
                                have[Y+dy[k]][X+dx[k]]=1;
                                q.push({Y + dy[k],X + dx[k] });
                            }
                        }
                    }
                }
            }
        }
    }
    cout << res << endl;
}