#include <cstdio>

#define FOR(i, l, r) for(int i = (l)    ; i <  (r); i++)
#define REV(i, l, r) for(int i = (r) - 1; i >= (l); i--)
#define INC(i, n) FOR(i, 0, n)
#define DEC(i, n) REV(i, 0, n)
#define INC1(i, n) FOR(i, 1, (n) + 1)
#define DEC1(i, n) REV(i, 1, (n) + 1)

typedef long long   signed int LL;
typedef long long unsigned int LU;

template<typename T> inline T abs(T x) { return (x > 0 ? x : -x); }

int x, y, l;

int main() {
	scanf("%d%d%d", &x, &y, &l);
	
	int xx = (abs(x) + l - 1) / l;
	int yy = (abs(y) + l - 1) / l;
	int r = (y < 0 ? 2 : (x != 0 ? 1 : 0));
	
	printf("%d\n", xx + yy + r);
	
	return 0;
}