#include<bits/stdc++.h>
using namespace std;
int main(){
 int x,y,l;
 cin>>x>>y>>l;
 int ans=0;
 if(y>=0){
  ans+=y;
 }else{
  ans+=1+abs(y);
 }
 if(x!=0){
  ans+=1+abs(x);
 }
 cout<<ans<<endl;
 return 0;
}