#include<iostream>
#include<string>
#include<algorithm>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<map>
#include<vector>
using namespace std;
typedef long long int ll;

int main(){

  int x, y, r;
  cin >> x >> y >> r;
  cout << abs(x)+abs(y)+(int)(r*sqrt(2))+1 << endl;

  return 0;
}