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

#define ll long long
#define vvi vector<vector<int>>
#define vec vector
#define pq priority_queue
#define all(v) (v).begin(), (v).end()
#define uniqueV(x) sort(x.begin(), x.end()); x.erase(unique(x.begin(), x.end()), x.end());
#define rep(i, n) for (int (i) = (0); (i) < (n); ++(i))
#define repp(i, m, n) for (int (i) = (m); (i) < (n); ++(i))
#define dbg(x) cerr << #x << ": " << x << endl;
#define dbg2(x, y) cerr<<"("<<#x<<", "<<#y<<") = "<<"("<<x<<", "<<y<<")"<<endl;
#define dbg3(x, y, z) cerr<<"("<<#x<<", "<<#y<<", "<<#z<<") = "<<"("<<x<<", "<<y<<", "<<z<<")"<<endl;
#define dbgB(value, size) cerr<<#value<<": "<<bitset<size>(value) << endl;
#define line() cerr << "---------------" << endl;

const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const double PI = 3.14159265358979323846;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }

template<typename T>
void printA(vector<T> &printArray, char between = ' ') {
   int paSize = printArray.size();
   for (int i = 0; i < paSize; i++) { cerr << printArray[i] << between;}
   if (between != '\n') {cerr << endl;}
}

// ------------------------------------------------------------------------------------------

int H, W;
bool B[3001][3001];

void print() {
   rep (i, H) {
      rep (j, W) {
         cout << B[i][j];
      }
      puts("");
   }
}

void dfs(int y, int x) {
   B[y][x] = 0;
   rep (i, 4) {
      int ny = y + dy[i], nx = x + dx[i];
      if (ny < 0 || ny >= H || nx < 0 || nx >= W) continue;
      if (B[ny][nx] == 0) continue;
      dfs(ny, nx);
   }
}

struct P {
   int y, x;
};

void bfs(int sy, int sx) {
   queue<P> Q;
   Q.push({sy, sx});

   while (Q.size()) {
      P p = Q.front(); Q.pop();
      int y = p.y, x = p.x;
      B[y][x] = 0;
      rep (i, 4) {
         int ny = y + dy[i], nx = x + dx[i];
         if (ny < 0 || ny >= H || nx < 0 || nx >= W) continue;
         if (B[ny][nx] == 0) continue;
         Q.push({ny, nx});
      }
   }
}

int main() {
   cin >> H >> W;
   rep (i, H) {
      rep (j, W) {
         cin >> B[i][j];
      }
   }

   int ans = 0;
   rep (i, H) {
      rep (j, W) {
         if (B[i][j]) {
            ans++;
            // dfs(i, j);
            bfs(i, j);
         }
      }
   }

   cout << ans << endl;

   return 0;
}