#include<iostream>
#include<cstdlib>

using namespace std;


int equ(int x,int y,int r){
        return abs(x)+abs(y)+(1.4142*r);
}

int main(void){
        int x,y,r;

        cin>>x>>y>>r;

        cout<<equ(x,y,r)+1<<endl;

        return 0;
}