#include<iostream>
#include<algorithm>
using namespace std;
int a,b,s;
main()
{
	cin>>a>>b>>s;
	if(abs(a-s)<=abs(b-s)||s==1)
	{
		cout<<abs(a-s)+s<<endl;
	}
	else if(a>0)
	{
		cout<<abs(b-s)+min(abs(a-s),s-1)+a<<endl;
	}
	else
	{
		cout<<abs(b-s)+s+1<<endl;
	}
}