#include <bits/stdc++.h>

using namespace std;

int main() {
    int x, y, n;
    cin >> x >> y >> n;
    int ans = (abs(x) + n - 1) / n + (abs(y) + n - 1) / n + ((x * y == 0) ? 0 : 1);
    cout << ans << endl;
    return 0;
}