#include<algorithm>
#include<cmath>
#include<cstdio>
#include<functional>
#include<iomanip>
#include<iostream>
#include<map>
#include<numeric>
#include<queue>
#include<set>
#include<string>
#include<utility>
#include<vector>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const ll MOD = 1000000007;
#define rep(i,n) for(int i=0;i<n;i++)
#define repl(i,s,e) for(int i=s;i<e;i++)
#define reple(i,s,e) for(int i=s;i<=e;i++)
#define revrep(i,n) for(int i=n-1;i>=0;i--)
#define all(x) (x).begin(),(x).end()

int H, W;

bool IsInRange(int w, int h)
{
	return 0 <= w && w <= W - 1 && 0 <= h && h <= H - 1;
}

int main()
{	
	cin >> H >> W;

	vector<vector<int>> A(W, vector<int>(H, 0));

	rep(h, H)
		rep(w, W)
			cin >> A[w][h];

	ll count = 0;

	rep(h, H)
	{
		rep(w, W)
		{
			if (A[w][h] != 1) continue;
			count++;

			queue<pair<int, int>> q;
			q.emplace(w, h);

			//幅優先探索
			while (!q.empty())
			{
				auto p = q.front(); q.pop();
				auto x = p.first;
				auto y = p.second;

				if (A[x][y] != 1) continue;
				A[x][y] = -1;

				if (IsInRange(x - 1, y))q.emplace(x - 1, y);
				if (IsInRange(x + 1, y))q.emplace(x + 1, y);
				if (IsInRange(x, y - 1))q.emplace(x, y - 1);
				if (IsInRange(x, y + 1))q.emplace(x, y + 1);
			}
		}
	}
		
	cout << count << endl;

	return 0;
}