#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <fstream>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>
#include <numeric>


typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;







int main()
{

    int Q;
    Q = 1;
    //cin >> Q;

    while (Q--) {
        ll a, b, c;
        cin >> a >> b >> c;
        ll d = 10000;
        set<int>p;
        for (ll i = a; i <= b; i++) {
            int t = p.size();
            ll x = i * c;
            x %= 1000;
            x = 1000 - x;
            if (x == 1000)x = 0;
            d = min(d, x);
            p.insert(x);
            if (t == p.size())break;
        }
        cout << d << endl;
    }
    return 0;
}