rt，90pts，求

// CSP-J 2021 RP += INFINITY
#include<bits/stdc++.h>
//#define int long long
using namespace std;
int main(){
//signed main(){
//	freopen("candy.in", "r", stdin);
//	freopen("candy.out", "w", stdout);
	long long n, l, r;
	cin >> n >> l >> r;
	int maxn = -1;
	for (long long i = r; i >= l; --i){
		long long a = i / n;
		int b = i - a * n;
//		cout << i << " " << b << endl;
		maxn = max(maxn, b);
		if (maxn == n - 1) break;
	}
	cout << maxn << endl;
	return 0;
}