#include <iostream>
#define int long long
using namespace std;

int l, r, c;

signed main() {
	int i;

	cin >> l >> r >> c;

	int ans = 999;
	for (i = l; i <= min(r, l + 1000); i++) {
		int score = (1000 - c * i % 1000) % 1000;
		ans = min(ans, score);
	}

	cout << ans << endl;
	return 0;
}