#include <iostream>
#include <fstream>
#include <cmath>

using namespace std;

int main()
{

	ifstream in;
	ofstream out;
	long long int P, i = 0, o = 0, M=1, k;
	in.open("fact.in");
	in >> P;
	in.close();
	bool cifre = false;
	if (P == 0)
	{
		cifre = true;
		i = 1;
	}
	while (cifre == false)
	{
		o = 0;
		i = i + 1;
		if(i % 5 == 0 || i == 2 || i==4)
		{
			M = M*i;
			while(M%3==0) M=M/3;
		}
		k = M;
		if (i % 5 == 0)
		{
			while (k != 0)
			{
				if (k % 10 == 0)
				{
					o = o + 1;
					k = k / 10;
				}
				else
				{
					k = 0;
				}
			}
		}
		if (o == P)
		{
			cifre = true;

		}
		else if (o > P)
		{
			cifre = true;
			i = -1;
		}
	}
	out.open("fact.out");
	out << i << endl;
	out.close();
	return 0;
}