#include <stdio.h>
#include <stdlib.h>
FILE *in,*out;long long n,P,X,nr;
int main()
{ int i;
   in=fopen("fact.in","r");
   out=fopen("fact.out","w");
   fscanf(in,"%lld",&P);
for(i=5;nr<P;i=i+5)
   {
       X=i;

       while(X%5==0)
             {X=X/5;
             nr++;
             }

   }

if(nr>0)
{if(nr==P)
fprintf(out,"%lld",i-5);
else
       if(  nr>P)
   fprintf(out,"%d",-1);


}
else
fprintf(out,"%d",1);



   fclose(in);fclose(out);
    return 0;
}