using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var a = NList;
        var (l, r, c) = (a[0], a[1], a[2]);
        var ans = 1000L;
        for (long i = l; i <= r && i < l + 1000; ++i)
        {
            ans = Math.Min(ans, (1000 - i * c % 1000) % 1000);
        }
        WriteLine(ans);
    }
}