#include <stdio.h>
long su,k,i,p,n;
int main()
{
	FILE *pfile=fopen("fact.in","r");
	fscanf(pfile,"%ld",&p);
	fclose(pfile);
	su=0; i=1;
	while(i<p+1)
	{
		k=i*5; n=k;
		while(k%5==0)
		{
			k/=5;
			su+=1;
		}
		if(su==p) break;
		else i++;
	}
	if(p==0) n=1;
	FILE *out=fopen("fact.out","w");
	fprintf(out,"%ld",n);
	fclose(out);
	return 0;
}