#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
typedef long long ll;
using namespace std;

int main() {
    cin.tie(0)->sync_with_stdio(0);

    ll X, Y, L;
    cin >> X >> Y >> L;

    ll ans = 0;
    if (Y < 0)
        ans += 2;
    else if (X != 0)
        ans += 1;

    X = abs(X);
    Y = abs(Y);

    ans += (X + L - 1) / L + (Y + L - 1) / L;
    cout << ans << "\n";

    return 0;
}