#include <iostream>

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;


#define MAX_H 3000
#define MAX_W 3000


using namespace std;

int H,W;
int A[MAX_H][MAX_W];

void dfs(int x, int y){
    A[y][x] = 0;
    int nx, ny;
    
    //上
    nx=x; ny=y+1;
    if(ny<H && A[ny][nx]==1) dfs(nx,ny);
    
    //下
    nx=x; ny=y-1;
    if(ny>=0 && A[ny][nx]==1) dfs(nx,ny);

    
    //右
    nx=x-1; ny=y;
    if(nx>=0 && A[ny][nx]==1) dfs(nx,ny);
    //左
    nx=x+1; ny=y;
    if(nx<W && A[ny][nx]==1) dfs(nx,ny);
}

void solve(){
    int res = 0;
    for(int j=0;j<H;j++){
        for(int i=0;i<W;i++){    
            if(A[j][i]==1){
                dfs(i,j);
                res++;
            }
        }
    }
    cout << res << endl;
}

int main(){    
    cin >> H >> W;
    for(int j=0; j<H; j++) 
        for(int i=0; i<W;i++) 
            cin >> A[j][i]; 
    solve();
}