//(マンハッタン距離的に)最も遠い点が問題。
#include<iostream>
#include<cmath>
using namespace std;

int x, y, r;

double distance(double rad) {
	double X = x + r * cos(rad);
	double Y = y + r * sin(rad);
	return X + Y;
}

int main() {
	cin >> x >> y >> r;
	
	x = (x>0)?x:-x;
	y = (y>0)?y:-y;
	
	int ans = 0;
	double PAI = 3.14159265358979;
	double EPS1 = 1e-6;
	double EPS2 = 1e-8;
	for(double rad = -2.0 * PAI; rad <= 2.0 * PAI; rad += EPS1) {
		int T = distance(rad) - EPS2 + 1;
		ans = max(T, ans);
	}
	cout << ans << endl;
	return 0;
}