#include "stdafx.h"
#include "iostream"
using namespace std;
int main()
{
	long long n, ans = 0, q = 0;
	cin >> n;
	if (n<2)
	{
		cout << n << endl;
		return 0;
	}
	for (int i = 9; i >= 2; i--)
	{
		while (n%i == 0)
		{
			ans = ans * 10 + i;
			n = n / i;
			//cout << ans << endl;
		}
	}
	if (n != 1)
		cout << -1 << endl;
	else
	{
		while (ans > 0)
		{
			q = ans % 10 + q * 10;
			ans = (ans - ans % 10) / 10;
		}
		cout << q << endl;
	}
}