class OneSpot {
    int x;
    int y;
    public OneSpot(int x, int y) {
        this.x = x;
        this.y = y;
    }
    @Override
    public boolean equals(Object o) {
        OneSpot s = (OneSpot) o;
        return (s.x == x && s.y== y);
    }
    @Override
    public int hashCode() {
        return y * 100 + x;
    }
}


class Result {

    /*
     * Complete the 'connectedCell' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts 2D_INTEGER_ARRAY matrix as parameter.
     */
    public static void grow(OneSpot spot, Set<OneSpot> ones, int xmax,
                            int ymax, Set<OneSpot> seen,
        Set<OneSpot> ourgang) {
            for (int dx = -1 ; dx < 2; dx++) {
                for (int dy = -1; dy < 2; dy++) {
                    int nx = spot.x + dx;
                    int ny = spot.y + dy;
                    OneSpot nspot = new OneSpot(nx, ny);
                    if (ones.contains(nspot) && ! seen.contains(nspot)) {
                        ourgang.add(nspot);
                        seen.add(nspot);
                        grow(nspot, ones, xmax, ymax, seen, ourgang);
                    }
                }
            }   
        }

    public static int connectedCell(List<List<Integer>> matrix) {
    // Write your code here
        Set<OneSpot> ones = new HashSet<>();
        int ymax = matrix.size() - 1;
        int xmax = matrix.get(0).size() - 1;
        for (int y = 0; y <= ymax; y++) {
            for (int x = 0; x <= xmax; x++) {
                if (matrix.get(y).get(x) == 1) {
                    ones.add(new OneSpot(x, y));
                }
            }
        }
        int size = 0;
        Set<OneSpot> seen = new HashSet<>();
        for (OneSpot spot : ones) {
            Set<OneSpot> ourgang = new HashSet<>();
            if (seen.contains(spot)) {
                continue;
            }
            ourgang.add(spot);
            seen.add(spot);
            grow(spot, ones, xmax, ymax, seen, ourgang);
            if (ourgang.size() > size) {
                size = ourgang.size();
            }
        }
        return size;
    }
}