#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    ll l,r,c; cin >> l >> r >> c;
    ll res = 1000;
    for (int i = 0; i < 1000; ++i) {
        if (l+i > r) break;
        res = min(res, (-(l+i)*c+(ll)1e18)%1000);
    }
    cout << res << endl;
}