#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
#define vv(a,b,c,d) vector<vector<a> >(b,vector<a>(c,d))
#define vvv(a,b,c,d,e) vector<vector<vector<a> > >(b,vv(a,c,d,e))
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

const int D[] = { 0,-1,0,1,0 };

bool A[3001][3001];
void dfs(int y, int x) {
    A[y][x] = false;
    rep(i, 4) {
        int ny = y + D[i], nx = x + D[i + 1];
        if (A[ny][nx])dfs(ny, nx);
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);

    int H, W, re = 0;
    cin >> H >> W;
    rep(y, H)rep(x, W)cin >> A[y + 1][x + 1];
    rep(y, H)rep(x, W)if (A[y + 1][x + 1]) {
        re++;
        dfs(y + 1, x + 1);
    }
    cout << re << endl;
}