import java.util.Scanner; public class Main48 { public static void main(String[] args) { Main48 p = new Main48(); } public Main48() { Scanner sc = new Scanner(System.in); int x = sc.nextInt(); int y = sc.nextInt(); int l = sc.nextInt(); solve(x, y, l); } public void solve(int x, int y, int l) { int res = (Math.abs(x)-1)/l + 1 + (Math.abs(y)-1)/l + 1; if(y<0) res+=2; else if(Math.abs(x)>0) res++; System.out.println(res); } }