#include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
using namespace atcoder;
using ll = long long;

void fast_io() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
}

int main(void) {
    fast_io();
    ll l, r, c;
    cin >> l >> r >> c;
    ll ans = 1000;
    for (ll i = l; i <= min(r, l + 1000); i++) {
        ll q = c * i / 1000;
        ll x = 1000 * q - c * i;
        if (x < 0) x += 1000;
        ans = min(ans, x);
    }
    cout << ans << endl;
    return 0;
}