#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>

using namespace std;

int H,W;
bool A[10000][10000];

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

int solve(int y,int x){
    if (!A[y][x])
    {
        return 0;
    }
    A[y][x] = false;
    queue<pair<int,int> > q;
    q.push(make_pair(y,x));
    while(!q.empty())
    {
        int c_y = q.front().first;
        int c_x = q.front().second;
        q.pop();
        A[c_y][c_x] = false;

        for (int k = 0; k < 4; k++)
        {
            int ny = c_y + dy[k];
            int nx = c_x + dx[k];
            if (0 <= ny && ny < H && 0 <= nx && nx < W && A[ny][nx])
            {
                // solve(ny, nx);
                A[ny][nx] = false;
                q.push(make_pair(ny, nx));
            }
        }
    }

    return 1;
}

int main(){
    cin >> H >> W;
    for(int i = 0;i < H;i++)
    {
        for(int j = 0;j < W;j++)
        {
            cin >> A[i][j];
        }
    }

    int res = 0;
    for(int i = 0;i < H;i++)
    {
        for(int j = 0;j < W;j++)
        {
            res += solve(i,j);
        }
    }

    cout << res << endl;

    return 0;
}