public class KnightDistance {

	public static int dist(int x1, int y1, int x2, int y2) {
		int dx = Math.abs(x2 - x1);
		int dy = Math.abs(y2 - y1);
		int moves = Math.max((dx + 1) / 2, (dy + 1) / 2);
		moves = Math.max(moves, (dx + dy + 2) / 3);
		if (moves % 2 != (dx + dy) % 2)
			++moves;
		if (dx == 1 && dy == 0)
			return 3;
		if (dy == 1 && dx == 0)
			return 3;
		if (dx == 2 && dy == 2)
			return 4;
		return moves;
	}

	public static void main(String[] args) {

	}
}