#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long ll;
ll n,l,r,sum;
int main()
{
	freopen("candy.in","r",stdin);
	freopen("candy.out","w",stdout);
	scanf("%lld%lld%lld",&n,&l,&r);
	if(n+n>=l&&n+n>=r)
	{
		printf("%lld",r-n);
		return 0;
	}
	sum=l;
	while(sum%n!=0&&sum!=r)
	{
		sum++;
	}
	if(sum==r)
	{
		printf("%lld",sum%n);
	}
	else
	{
		printf("%lld",(sum-1)%n);
	}
	return 0;
}
//我永远喜欢射命丸文\aya