#include <bits/stdc++.h>
using namespace std;
long long n, l, r, maxs = -1, ans;

int main() {
	cin >> n >> l >> r;
	for (long long i = r; i >= l; i--) {
		ans = i % n;
		maxs = max(ans, maxs);
	}
	cout << maxs << " ";
	return 0;
}