#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

#include <vector>
#include <numeric>
#include <utility>
#include <cassert>

struct UnionFind {
public:
	using size_type = std::size_t;
	
private:
	size_type n;
	std::vector<int> dat;
	
public:
	UnionFind(size_type n) : n(n), dat(n, -1) {}
	
	size_type size(size_type x) {
		assert(x < n);
		return -dat[find(x)];
	}
	
	size_type find(size_type x) {
		assert(x < n);
		if (dat[x] < 0) return x;
		return dat[x] = find(dat[x]);
	}
	
	void unite(size_type x, size_type y) {
		assert(x < n);
		assert(y < n);
		x = find(x);
		y = find(y);
		if (x == y) return;
		if (dat[x] < dat[y]) std::swap(x, y);
		dat[x] += dat[y];
		dat[y] = x;
	}
	
	bool issame(size_type x, size_type y) {
		assert(x < n);
		assert(y < n);
		return find(x) == find(y);
	}
};

int main() {
	int H, W;
	cin >> H >> W;
	vector A(H, vector(W, false));
	REP(i, H) REP(j, W) {
		int a;
		scanf("%d", &a);
		A[i][j] = a;
	}
	
	UnionFind uf(H * W);
	constexpr int dx[]{1,0,-1,0}, dy[]{0,-1,0,1};
	REP(i, H) REP(j, W) {
		if (!A[i][j]) continue;
		REP(k, 4) {
			const int y = i + dy[k], x = j + dx[k];
			if (y < 0 || y >= H || x < 0 || x >= W) continue;
			if (!A[y][x]) continue;
			uf.unite(i * W + j, y * W + x);
		}
	}
	int ans = 0;
	REP(i, H) REP(j, W) if (A[i][j] == 1 && uf.find(i * W + j) == i * W + j) ++ans;
	cout << ans << endl;
}