#include <iostream>
#include <fstream>

using namespace std;

long NUM;

int main()
{
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    long i=5, nr=0,temp;
    bool divisible = true;
    fin>>NUM;
    while(nr<NUM)
    {
        temp=i;
        while(divisible)
        {
            if(temp%5==0){
                nr++;
                temp/=5;
                }
            else
                divisible=false;
        }
        divisible=true;
        i+=5;
    }
    if(nr == NUM)
    fout<<i-5;
    else
        fout<<"-1";
    return 0;
}