#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,R,L,maxn;
	cin>>n>>L>>R;
	while(R>L)
	{
		maxn = max(maxn,R%n);
		R--;
//		cout<<R<<" ";
	}
	cout<<maxn;
	return 0;
}