#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,l,r,max=0,k;
	cin>>n>>l>>r;
	for(int i=l;i<=r;i++){
		k=i%n;
		if(k>max) max=k;	
	}
	cout<<max;
return 0;}

/**************************************************************
	Problem: 2401
	User: fzy001
	Language: C++
	Result: Time Limit Exceed
****************************************************************/