#include<fstream.h>
#include<iostream.h>
int main ()
{
	long n,i,x,a,b;
	ifstream f("fact.in");
	ofstream g("fact.out");
	f>>n;
	f.close();
	x=n*5;
	i=25;
    a=0;
	b=1;
	while(i<=x) { if(x==i) { a=0; 
	                         b=0;
	                         g<<"-1";
	                         break;
	                         }
				  else a++;
				  i=i+100;
	              }
    if(b) g<<x-a*5;
	g.close();
	return 0;
}