#include <fstream>

using namespace std;

ifstream fin("fact.in");
ofstream fout("fact.out");

int p;

int main()
{
	fin >> p;
	if (p == 0)
		fout << 1;
	else
	{
		for (int i = 5; ; i += 5)
		{
			int x = i;
			while (x % 5 == 0)
			{
				x /= 5;
				p--;
			}
			if (p == 0)
			{
				fout << i;
				break;
			}
			else if (p < 0)
			{
				fout << -1;
				break;
			}
		}
	}
}