#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;


int main() {

    long X, Y, L;
    cin >> X >> Y >> L;

    long count = 0;
    // required rotations
    if (Y < 0) {
        count = 2;
    } else {
        if (X == 0) {
            count = 0;
        } else {
            count = 1;
        }
    }

    long absX = abs(X);
    long absY = abs(Y);

    if (absX % L != 0) {
        count += (absX / L + 1);
    } else {
        count += absX / L;
    }

    if (absY % L != 0) {
        count += (absY / L + 1);
    } else {
        count += absY / L;
    }

    cout << count << endl;

    return 0;

}