#include<stdio.h>

int fac(int n) {
if ( n == 0 )
	return 1;
else return n*fac(n-1);
}

int main(){
int n=0,p,i,k=0;
int res=0;
FILE *in,*out;

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


  if (p !=0){
	for (i=5;n<=p;i+=5){
		k=i;
		while(k%5==0){
			n+=1;
			k=k/5;
		}
	}
  if(n!=p) 
	res = -1;
  else res=i;
  }
	else res=1;		



fclose(in);
out = fopen("fact.out","w");
fprintf(out,"%d",res);
fclose(out);
return 0;
}