using System;

namespace Product_of_Digits
{
    class Program
    {
        static void Main(string[] args)
        {
            ulong n = Convert.ToUInt64(Console.ReadLine());
            ulong[] primos = { 2, 3, 5, 7 };
            ulong[] pr = new ulong[4];
            ulong suma = 0;

            if (n >= 10)
            {
                for (ulong i = 0; i < 4; i++)
                {
                    while (n % primos[i] == 0)
                    {
                        pr[i]++;
                        n /= primos[i];
                    }

                }
                if (n / 7 != 0)
                    Console.WriteLine("-1");
                else
                {
                    for (ulong i = 0; i < 4; i++)
                        suma += pr[i];
                    ulong[] print = new ulong[suma];
                    ulong[] printlargo = new ulong[suma];
                    ulong j = 0;
                    for (ulong i = 0; i <= 3; i++)
                    {
                        while (pr[i] > 0)
                        {
                            printlargo[j] = primos[i];
                            pr[i]--;
                            j++;
                        }
                    }
                    ulong k = suma - 1;
                    while (k >=0&&k<suma)
                    {
                        print[k] = printlargo[k];
                        j = 1;
                        if (j > k)
                            break;
                        while (print[k] * printlargo[k - j] < 10)
                        {
                            print[k] *= printlargo[k - j];
                            j++;
                            if (j >k)
                                break;
                        }
                        k -= j;
                    }
                    Array.Sort(print);
                    for (ulong i = 0; i < suma; i++)
                    {
                        if (print[i] != 0)
                        {
                            Console.Write("{0}", print[i]);
                        }
                    }
                }
            }
            else if (n > 0 && n < 10)
                Console.WriteLine("{0}", n);
            else
                Console.WriteLine("1{0}", n);
        }
    }
}