#pragma option -3 -r -Z -O2 -a
#include<fstream.h>


int main()
{

ifstream f("fact.in");
ofstream h("fact.out");
register unsigned long i=5,j=0,x,p;
f>>p;
while(j<p)
 {x=i;
 if(x%25==0)  while(x%5==0) j++,x/=5;
 i+=5;
 j++;
 }
h<<i;


return 0;
}