#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
int H,W;
int V[3000][3000];
void dfs(int h,int w){
    V[h][w] = 0;
    int dx[] = {0,0,1,-1}, dy[] = {1,-1,0,0};
    rep(i,0,4){
        int x = dx[i] + w, y = dy[i] + h;
        if(x < 0 || x >= W || y < 0 || y >= H)continue;
        if(V[y][x])dfs(y,x);
    }
}
main(){
    cin >> H >> W;
    rep(i,0,H)rep(j,0,W)cin >> V[i][j];
    int cnt = 0;
    rep(i,0,H)rep(j,0,W){
        if(V[i][j]){
            cnt++;
            dfs(i,j);
        }
    }
    cout << cnt << endl;
}