#include <iostream>
#include <fstream>
using namespace std;

unsigned long N,aux;

int main()
{
    ifstream f("fact.in");
    ofstream g("fact.out");
    int x=1;
    signed long P;
    f>>P;
    f.close();
    if(P==0)
        g<<x;
    else
    {
        do{
            N+=5;
            aux=N;
            do{
                N/=5; x=N%5;
                P--;
            }while(!(x));
            N=aux;
        }while(P);
        g<<N;
    }
}