#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>

using namespace std;

#define REP(i,n)	for(int i=0;i<(n);++i)
#define REPS(i,s,t)	for(int i=(s);i<(t);++i)
#define PER(i,n)	for(int i=0;i>(n);--i)
#define PERS(i,s,t)	for(int i=(s);i>(t);--i)

#define INF 		2000000007
#define MINF		-200000007
#define MOD			17 	
// 2^20

#define MAX 		200005

typedef unsigned int 			uint;
typedef unsigned long long int	ull;
typedef long long int 			ll;

template<typename T>
istream& operator >> (istream& is, vector<T>& vec){
  for(T& x: vec) is >> x;
  //for(int i=0; i<vec.size(); i++) is >> x[i]; とかでもいいです。
  return is;
}

//int dp[MAX];
int H,W;

void check(vector<vector<int> > &A,int x,int y){
	if(0>x||x>=H)return;
	if(0>y||y>=W)return;
	if(A[x][y]==0) return;
	else{
		A[x][y] = 0;
		check(A,x+1,y);
		check(A,x,y+1);
		check(A,x-1,y);
		check(A,x,y-1);
	}
}

int main(){
	cin>>H>>W;
	int cnt=0;

	vector<vector<int> > A(H,vector<int>(W,false));
	cin>>A;

	REP(i,H){
		REP(j,W){
			if(A[i][j]==0)continue;
			cnt++;
			check(A,i,j);
		}
	}

	cout << cnt << endl;

	return 0;
}