#include<fstream.h>
int main()   
{   
ifstream f("fact.in");   
ofstream g("fact.out");   
 long long p,n,i,j,a,b;
 f>>p;
 int gasit=0;
 n=1;
 while(gasit==0)
 {
 
    j=n;
    while(j%2==0)
    {
     j=j/2;
     a++;
    }
    j=n;
    while(j%5==0)
    {
     j=j/5;
     b++;
    }
  if(a>b)
      if(b==p)
      {
        gasit=1;
         g<<n;
      }
      else
       if(a==p)
       {
	gasit=1;
	g<<n;
       }
   n++;
  }
 return 0;   
}