#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
long long s,n,r,l,i,j,ans = -1e9;
int main()
{
	//freopen("candy.in","r",stdin);
	//freopen("candy.out","w",stdout);
	cin>>n>>l>>r;
	for(i = l;i <= r;i++)
	{
		ans = max(ans,(i % n));
		if(ans == n - 1)break;
	}
	cout<<ans;
	//fclose(stdin);
	//fclose(stdout);
	return 0;
 }