#include<bits/stdc++.h>	
using namespace std;
int n, l, r; 
int ans = -1;
signed main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	cin >> n >> l >> r;
	for(int i=l;i<=r;i++){
		ans = max(i % n, ans);
	}
	cout << ans;
}