#include <iostream>
#include <fstream>
#include <map>
#include <string>


using namespace std;

int main()
{
    int N,P;
    ifstream f("fact.in");
    ofstream g("fact.out");
    f>>P;
    if(P < 0)
        g<<"-1";
    else
    {int nrPare = 0;
    int multCinci = 0;
    N = 0;
    while(nrPare < P || multCinci < P)
    {
        N++;
        if(N%2 == 0)
            nrPare++;
        if(N%5 == 0)
            {   multCinci++;
                int x = N;
                x = x/5;
                while(x%5 == 0)
                {
                    multCinci++;
                    x = x/5;
                }
            }
        if(N%2 == 0 && N%5 == 0)
        {
            int x = N;
            x = x/10;
            while(x)
            {
                if(x%10 == 0)
                {
                    nrPare++;
                    multCinci++;
                }
                x = x/10;
            }
        }
    }

    if(nrPare == P || multCinci == P)
        g<<N;
    else
    {
        int x = -1;
        g<<x;
    }
    }

}