#include <iostream>
#include <vector>
#include <sstream>
#include <stdlib.h>
#include <math.h>
using namespace std;


int main()
{
	string in;
	int temp;
	vector<int> v;

	getline(cin,in);
	stringstream ss(in);
	
	while(!ss.eof()){
		ss>>temp;
		v.push_back(temp);
		ss.ignore();
	}

	int x,y,r;
	x = abs(v.at(0));
	y = abs(v.at(1));
	r = v.at(2);
	
	int t = ceil(x + y + sqrt(2)*r);
	cout<<t<<endl;
	return 0;
}