#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<cmath>
#include<cstdio>
using namespace std;
int main(){
    int x,y,r;
    cin >> x >> y >> r;
    if(x<0) x*=-1;
    if(y<0) y*=-1;
    cout << abs(x) + abs(y) + (int)(r*sqrt(2)+1);
    return 0;
}