#include <stdio.h>
#include <malloc.h>
char str[60000];
int str_len = 0;


/// <summary>
/// 入力された数字を返す
/// </summary>
/// <returns></returns>
int ReadNum() {
	int negate = 0;
	char c = getchar();
	int num = 0;
	int numCnt = 0;
	while (c != '\n') {
		if (c == '-') {
			negate = 1;
		}
		else {
			num = num * 10 + c - '0';
		}
		
		c = getchar();
	}
	if (negate == 1) {
		num *= -1;
	}
	return num;
}

int main()
{
	int x = ReadNum();
	int y = ReadNum();
	int l = ReadNum();
	int order;
	if ((x > 0 && y > 0) || (x < 0 && y > 0)) {
		order = 1;
	}
	if ((x > 0 && y < 0) || (x < 0 && y < 0)) {
		order = 2;
	}
	if ((x == 0 && y == 0) || (x == 0 && y > 0)) {
		order = 0;
	}
	if ((y == 0 && x < 0) || (y == 0 && x > 0)) {
		order = 1;
	}
	if (x == 0 && y < 0) {
		order = 2;
	}

	//printf("%d\n",order);

	if (x < 0) {
		x *= -1;
	}
	if (y < 0) {
		y *= -1;
	}

	if (x != 0) {
		order += x / l;
		if (x % l != 0) {
			order++;
		}
	}
	if (y != 0) {
		order += y / l;
		if (y % l != 0) {
			order++;
		}
	}
	printf("%d\n",order);
}