#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int a,b,p,x,y,n,i,k;
int main()
{
  i=5;
    f>>p;

while (1==1)
    {
        x=i;
     while (x%5==0)
     {
      k=k+1;
      x=x/5;
     }
     if (k>=p)  break;
     i=i+5;
    }
g<<i;

  f.close();
  g.close();
    return 0;
}