#include "bits/stdc++.h"
#define ALL(obj) (obj).begin(),(obj).end()
#define RALL(obj) (obj).rbegin(),(obj).rend()
#define REP(i, n) for(int i = 0; i < (int)(n); i++)
#define REPR(i, n) for(int i = (int)(n); i >= 0; i--)
#define FOR(i,n,m) for(int i = (int)(n); i < int(m); i++)
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = MOD - 1;
const ll LLINF = 4e18;

int main() {
    int h, w; cin >> h >> w;
    vector<vector<int>> F(h, vector<int>(w));
    REP(i, h) {
        REP(j, w) {
            cin >> F[i][j];
        }
    }
    int ans = 0;
    REP(i, h) {
        REP(j, w) {
            if (F[i][j] == 1) {
                stack<pair<int, int>> sta;
                sta.push({i,j});
                while (!sta.empty()) {
                    pair<int, int> p = sta.top(); sta.pop();
                    F[p.first][p.second] = 0;
                    if (i < h - 1 && F[i + 1][j] == 1) sta.push({i + 1, j});
                    if (j < w - 1 && F[i][j + 1] == 1) sta.push({i, j + 1});
                    if (i > 0 && F[i - 1][j] == 1) sta.push({i - 1, j});
                    if (j > 0 && F[i][j - 1] == 1) sta.push({i, j - 1});
                }
                ans++;
            }
        }
    }
    cout << ans << endl;
    getchar(); getchar();
}