# include <iostream>
# include <fstream>
using namespace std;
int main()
{
    int n=5,p,cn;
    ifstream f("fact.in");
    ofstream g("fact.out");
    f>>p;
    if(p==0)g<<1;
    else if(p==1)g<<5;
    else
    {--p;
        while(p>0)
        {
            n+=5;
            cn=n;
            while(cn%5==0)
            {
                --p; cn/=5;
            }
        }
        g<<n;
    }
}