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