#include <bits/stdc++.h>
using namespace std;
int n,l,r,ans;
int main() {
	freopen("candy.in","r",stdin);
	freopen("candy.out","w",stdout);
	cin>>n>>l>>r;
	for(int i=l;i<=r;i++){
		ans=max(ans,i%n);
	}
	cout<<ans;
    return 0;
}