#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<short> dfs(int row, int col, vector<short> field,
                  int H, int W) {
  field[row * W + col] = 0;
  if((row - 1 >= 0) && (field[(row - 1) * W + col] == 1)) {
    field = dfs(row - 1, col, field, H, W);
  }
  if((row + 1 < H) && (field[(row + 1) * W + col] == 1)) {
    field = dfs(row + 1, col, field, H, W);
  }
  if((col - 1 >= 0) && (field[row * W + col - 1] == 1)) {
    field = dfs(row, col - 1, field, H, W);
  }
  if((col + 1 < W) && (field[row * W + col + 1] == 1)) {
    field = dfs(row, col + 1, field, H, W);
  }
  return field;
}

int main(void) {
  int H, W;
  cin >> H >> W;
  vector<short> field(H * W);
  for(int i = 0; i < H * W; i++) {
    cin >> field[i];
  }
  int ans = 0;
  for(int i = 0; i < H; i++) {
    for(int j = 0; j < W; j++) {
      if(1 == field[i * W + j]) {
        field = dfs(i, j, field, H, W);
        ans++;
      }
    }
  }
  cout << ans << endl;
  return 0;
}