import java.util.Scanner; public class No48 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int X = sc.nextInt(); int Y = sc.nextInt(); int L = sc.nextInt(); int ans = 0; ans += (Math.abs(Y) + L - 1) / L; ans += (Math.abs(X) + L - 1) / L; if(Y < 0){ ans++; } if(X != 0){ ans++; } System.out.println(ans); } }