#include <bits/stdc++.h>

using namespace std;

#define rep(i, n) for(int i = 0; i < (int)n; ++i)
#define FOR(i, a, b) for(int i = a; i < (int)b; ++i)
#define rrep(i, n) for(int i = ((int)n - 1); i >= 0; --i)

typedef long long ll;
typedef long double ld;

const ll INF = 1e18;
const int Inf = 1e9;
const double EPS = 1e-9;
const int MOD = 1e9 + 7;

int dx[4] = {0, 0, 1, -1};
int dy[4] = {1, -1, 0, 0};

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(0);
    int h, w;
    cin >> h >> w;
    vector<vector<int> > g(h, vector<int>(w));
    rep (i, h) rep (j, w) cin >> g[i][j];
    int res = 0;
    rep (i, h) {
        rep (j, w) {
            if (g[i][j] != 1) continue;
            res++;
            queue<pair<int, int> > q;
            q.push(make_pair(i, j));
            while (!q.empty()) {
                int x, y;
                x = q.front().first, y = q.front().second;
                q.pop();
                rep (k, 4) {
                    int nx, ny;
                    nx = x + dx[k], ny = y + dy[k];
                    if (nx < 0 || ny < 0 || nx >= h || ny >= w) continue;
                    if (g[nx][ny] != 1) continue;
                    q.push(make_pair(nx, ny));
                    g[nx][ny] = 0;
                }
            }
        }
    }
    cout << res << endl;
    
    return 0;
}