#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
using namespace std;
int main()
{
	int n,i,j,q,h,ans;
	cin>>n>>i>>j;
	if(i==j&&i==n-i+1&&j==n-j+1)
	{
		cout<<n*n;
		return 0; 
	}
	q=min(min(i,j),min(n-i+1,n-j+1));
	h=4*(n-q+1)*(q-1);
	if(q==i)
	ans=h+1+j-q;
	if(n-j+1==q)
	ans=h+n-2*(q-1)+i-q;
	if(n-i+1==q)
	ans=h+n-3*(q-1)+j-q-1;
	if(j==q&&i!=q)
	ans=h+n-3*(q-1)-1+i-q;
	cout<<ans;
	return 0;
 }