/*
    No.48 ロボットの操縦
    https://yukicoder.me/problems/no/48
*/
#include <bits/stdc++.h>
using namespace std;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int dist = 0;
    int x, y, l;
    cin >> x >> y >> l;
    x = abs(x);
    y = abs(y);

    dist += (x / l);
    dist += (x % l);

    dist += (y / l);
    dist += (y % l);
    if (x != 0 && y != 0)
        dist += 1;
    cout << dist << endl;
}