#include<stdio.h>

int main(){
int a,p,k,i,aux;

FILE *f=fopen("fact.in","r");
fscanf(f,"%d",&p);
fclose(f);




i=0;
k=0;

  while(k<p){
  i+=5;
  aux=i;
     while(aux%5==0){
     k++;
     aux=aux/5;
     }

  }


FILE *g=fopen("fact.out","w");

a=-1;
  if(k==p){
  fprintf(g,"%d",i);
  }
    else fprintf(g,"%d",a);

fclose(g);



return 0;
}