#include <bits/stdc++.h>
using namespace std;

typedef long long   signed int LL;
typedef long long unsigned int LU;

#define incID(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); i++)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); i--)
#define  inc(i, n) incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define  dec(i, n) decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)

#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))

#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define PQ priority_queue

#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
#define  FOR(it, v) for(auto it =  v.begin(); it !=  v.end(); ++it)
#define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it)

template<typename T> bool   setmin(T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool   setmax(T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }

// ---- ----

int h, w;
bool a[3000][3000];

int main() {
	cin >> h >> w;
	inc(i, h) {
	inc(j, w) {
		int v; cin >> v;
		a[i][j] = (v == 1);
	}
	}
	
	int ans = 0;
	inc(i, h) {
	inc(j, w) {
		stack<pair<int, int>> st;
		if(a[i][j]) {
			a[i][j] = false;
			ans++;
			st.emplace(i, j);
		}
		while(! st.empty()) {
			auto e = st.top(); st.pop();
			int di[4] = { 1, 0, -1,  0 };
			int dj[4] = { 0, 1,  0, -1 };
			inc(k, 4) {
				int ii = e.FI + di[k];
				int jj = e.SE + dj[k];
				if(inID(ii, 0, h) && inID(jj, 0, w) && a[ii][jj]) {
					a[ii][jj] = false;
					st.emplace(ii, jj);
				}
			}
		}
	}
	}
	
	cout << ans << endl;
	
	return 0;
}