using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = long.Parse(ReadLine());
        var sq = (int)Math.Ceiling(Math.Sqrt(n)) + 1;
        for (var i = 2L; i <= sq; ++i)
        {
            if (Check(n, i))
            {
                WriteLine(i);
                return;
            }
        }
        for (var i = sq; i > 0; --i)
        {
            if (n % i == 0 && n / i > 2 && n / i - 1 > i)
            {
                WriteLine(n / i - 1);
                return;
            }
        }
    }
    static bool Check(long n, long p)
    {
        var list = new List<long>();
        while (n > 0)
        {
            list.Add(n % p);
            if (list.Count > 1 && list[^1] != list[^2]) return false;
            n /= p;
        }
        return true;
    }
}