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; if (n == 1) { WriteLine(1); return; } var inv = ModInv(10, n); var root = (int)Math.Sqrt(n); var set = new HashSet<long>(); var tmp = (long)inv; for (var i = 0; i < root; ++i) { set.Add(tmp); tmp = tmp * inv % n; } for (var i = 0; i < n; i += root) { var pr10 = Exp(10, i, n); if (set.Contains(pr10)) { tmp = pr10; for (var j = i; j < i + root; ++j) { if (tmp == inv) { WriteLine(j + 1); return; } tmp = tmp * 10 % n; } } } } // 拡張ユークリッド互除法 ax + by = gcd(a, b) を満たす x, y を求める public static (long g, long x, long y) XGcd(long a, long b) { long x0 = 1, y0 = 0, x1 = 0, y1 = 1; while (b != 0) { var q = a / b; var prevA = a; a = b; b = prevA % b; var prevX0 = x0; var prevY0 = y0; x0 = x1; x1 = prevX0 - q * x1; y0 = y1; y1 = prevY0 - q * y1; } return (a, x0, y0); } // a ^ -1 mod m を求める static int ModInv(int a, int mod) { var (_, x, _) = XGcd(a, mod); return (int)((x + mod) % mod); } static long Exp(long n, long p, int mod) { long _n = n % mod; var _p = p; var result = 1L; if ((_p & 1) == 1) result *= _n; while (_p > 0) { _n = _n * _n % mod; _p >>= 1; if ((_p & 1) == 1) result = result * _n % mod; } return result; } }