#include <bits/stdc++.h>

#define REP(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))

using namespace std;

typedef int64_t ll;

const int INF = 1e8;
const double EPS = 1e-10;
const double PI = 3.141592653589;
int main() {
    ios_base::sync_with_stdio(false);

    double x, y, r;
    cin >> x >> y >> r;    
    x = abs(x);
    y = abs(y);

    double k = x + y + sin(PI/4)*r + cos(PI/4)*r;
    
    cout << ceil(k) << endl;  

}