#pragma GCC target("avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	long long L, R, C;
	cin >> L >> R >> C;
	long long ans = 1000;
	for( long long x = L; x <= min(R, L+1000LL); x++ ) {
		ans = min(ans, (1000-x*C%1000)%1000);
	}
	cout << ans << endl;
}