#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1000000007;
const int MAX_N = 3010;

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

#define REP(i,n) for((i)=0;(i)<(int)(n);(i)++)

int field[MAX_N][MAX_N];
int h, w;
typedef pair<int, int> P;

void dfs(int x, int y){
    stack<P> s;
    s.push(P(x, y));

    while(s.size()){
        P p = s.top(); s.pop();
        field[p.first][p.second] = 0;

        for (int i = 0; i < 4; i++){
            int nx = p.first + dx[i];
            int ny = p.second + dy[i];
            if (0 <= nx && nx < h && 0 <= ny && ny < w && field[nx][ny]){
                s.push(P(nx, ny));
            }
        }
    }
}

int main(){
    cin >> h >> w;
    int i, j;
    REP(i, h) REP(j, w) cin >> field[i][j];
    
    int ans = 0;
    REP(i, h) REP(j, w){
        if (field[i][j]){
            dfs(i, j);
            ans++;
        }
    }

    cout << ans << endl;

    return 0;
}