#include <iostream>
#include <cmath>
using namespace std;

int main() {
	int x, y, r;
	double b, px, py;
	cin >> x >> y >> r;
	x = abs(x);
	y = abs(y);
	px = x + r / sqrt(2);
	py = y + r / sqrt(2);

	b = px + py;
	cout << (int)b + 1 << endl;

	return 0;
}