#include<stdlib.h>
#include<stdio.h>

int n;
int main(){
	int i,div,a;
	FILE *fin=fopen("fact.in","r");
	FILE *fout=fopen("fact.out","w");
	fscanf(fin,"%d",&n);
	if(n==0)
		fprintf(fout,"1\n");
	else{
		for(i=1,div=5;i<=n;div=div+5)
		{	
			a=div;
			while(a%5==0&&i<=n)
			{
				i++;
				a=a/5;
			}
		}
		if(a%5||n==1)
			fprintf(fout,"%d\n",div-5);
		else
			fprintf(fout,"-1\n");
	}
	return 0;
}