#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    ll L, R, C, ans=1e18, mi;
    cin >> L >> R >> C;
    mi = max(R-1000, L);
    for (ll i=mi; i<=R; i++){
        if (i*C >= 1000) ans = min(i*C % 1000, ans);
        ans = min(1000LL - (i*C) % 1000, ans);
    }

    cout << ans << endl;

    return 0;
}