#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

long getDirCmdCntZeroToGoal(long goalX, long goalY)
{
	int cmdCnt = 0;
	if (goalX!=0) {
		++ cmdCnt;
		if (goalY<0) {
			++ cmdCnt;
		}
	}
	else {
		if (goalY<0) {
			cmdCnt = 2;
		}
	}
	return cmdCnt;
}
long getMoveCmdCntZeroToGoal(long dst, long minLen)
{
	int cmdCnt = 0;
	if (dst==0) {
		return 0;
	}
	long goal  = abs(dst);
	long mvLen = min(goal, minLen);
	long mvCnt = goal/mvLen;
	cmdCnt += mvCnt;
	if ( goal-(mvLen*mvCnt) > 0 ) {
		cmdCnt += 1;
	}
	return cmdCnt;
}

int main(int argc, char**argv)
{
	long gx, gy, l;
	cin >> gx >> gy >> l;

	int cmdCnt = 0;
	cmdCnt += getDirCmdCntZeroToGoal( gx, gy );
	cmdCnt += getMoveCmdCntZeroToGoal( gx, l);
	cmdCnt += getMoveCmdCntZeroToGoal( gy, l);
	cout << cmdCnt << endl;
	return 0;
}