#include<iostream>
using namespace std;
int n,x,y;
int solve(int n,int x,int y)
{
	if(x==1){
		return y;
	}
	if(y==n)
	{
		return n-1+x;
	}
	if(x==n)
	{
		return 3*n-1-y;
	}
	if(y==1)
	{
		return 4*n-2-x; 
	}
	return 4*(n-1)+solve(n-2,x-1,y-1);
}
int main(){
	cin>>n>>x>>y;
	cout<<solve(n,x,y)<<endl;
	return 0;
}