请大家帮忙看一下哪里有bug，感谢

#include<bits/stdc++.h>
using namespace std;
int main()
{//freopen("candy.in","r",stdin);
	//freopen("candy.out","w",stdout);
	long long n,l,r;
	cin>>n>>l>>r;
	long long a=l%n;
	long long b=r%n;
	if(b<a)
	{
		cout<<n-1;
	}
	else
	{
		if(n==0)
		{
			cout<<0;
			return 0;
		}
		if(a==b&&l==r)
		cout<<b;
		else
		{
			if(a==b)
			cout<<n-1;
			else
			cout<<b;
		}
	}
return 0;
}