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();
    static long[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        WriteLine(All(n));
    }
    static int All(int n)
    {
        var tmp = 10L % n;
        for (var i = 0; i < n; ++i)
        {
            if (tmp == 1) return i + 1;
            tmp = tmp * 10 % n;
        }
        return 0;
    }
}