#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 h, w;
vector<vector<int> > g;

void dfs(int sx, int sy) {
    g[sx][sy] = 0;
    rep (i, 4) {
        int nx, ny;
        nx = sx + dx[i];
        ny = sy + dy[i];
        if (nx < 0 || ny < 0 || nx >= h || ny >= w) continue;
        if (g[nx][ny] == 0) continue;
        dfs(nx, ny);
    }
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(0);
    cin >> h >> w;
    g = vector<vector<int> >(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;
            dfs(i, j);
            res++;
        }
    }
    cout << res << endl;
    
    return 0;
}