#ifndef hari64
#include <bits/stdc++.h>
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#define debug(...)
#else
#include "util/viewer.hpp"
#define debug(...) viewer::_debug(__LINE__, #__VA_ARGS__, __VA_ARGS__)
#endif
using namespace std;
constexpr int INF = 1001001001;
constexpr long long INFll = 1001001001001001001;
template <class T>
bool chmax(T& a, const T& b) {
    return a < b ? a = b, 1 : 0;
}
template <class T>
bool chmin(T& a, const T& b) {
    return a > b ? a = b, 1 : 0;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int L, R, C;
    cin >> L >> R >> C;

    vector<bool> seen(1000);

    long long ans = INFll;
    for (long long i = L; i <= R; i++) {
        long long oturi = 1000 - i * C % 1000;
        if (oturi == 1000) {
            oturi = 0;
        }
        chmin(ans, oturi);
        if (seen[oturi]) {
            break;
        }
    }

    cout << ans << endl;

    return 0;
}