#include<iostream.h>
#include<stdio.h>
int main ()
{long long P,N=0,N2,c,c2;
int truth=-1,truth2=1;
freopen ("fact.in", "rt" ,stdin);
freopen ("fact.out","wt" ,stdout);
cin>>P;
if (P==0) cout<<truth2;
else{for (N=25,c2=1,c=6;P>=c;N=N+25,P=P-c,c2++) if (c2==5) {c2=0; c++;}
          while (P>0) {N2=N;
                       while (N2%5) {P--;
                                     N2=N2/5;}
		       N=N+5;}}
if (P<0) cout<<truth;
if (P==0 && N!=0) cout<<N;
return 0;}