#include <bits/stdc++.h>
using namespace std;
int n,l,r;
int main(){
	freopen("candy.in","r",stdin);
	freopen("candy.out","w",stdout);
	//ios::sync_with_stdio(0);
	//cin.tie(0);
	//cout.tie(0);
	cin>>n>>l>>r;
	int Max=-99999999;
	int t;
	for(int i=l;i<=r;i++){
		t=i;
		loop:if(t-n>=0){
			t=t-n;
			goto loop;
		}
		Max=max(Max,t);
	}
	cout<<Max;
	//cout<<endl<<clock();
	return 0;
} 

洛谷自测100/yiw