#include <bits/stdc++.h>

using namespace std;

int main()
{
	int n,l,r;
	cin >> n >> l >> r;
	int max_ = 0;
	for (int i=l;i<=r;i++)
	{
		int flag = i;
		while (flag >= n)
		{
			flag -= n;
		}
		if (max_ < flag) max_ = flag;
	}
	cout << max_;
	return 0;
}