#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int a,b,s;
  cin>>a>>b>>s;
  Int ans=0;
  if(s==0){
    ans=0;
  }else if(s==1||abs(a-s)<=abs(b-s)){
    ans=abs(a-s)+s;
  }else{
    ans=min(abs(b-s)+s-1+abs(a-1)+1,abs(b-s)+abs(a-s)+a);
  }
  cout<<ans<<endl;
  return 0;
}