#include <cstdio>
using namespace std;
int legendre(int n){
int s=0;
long long numitor;
numitor=5;
while(numitor<=n){
	s=s+n/numitor;
	numitor*=5;
}
return s;
}
int bs(int st,int dr,int val){
int med,last;
while(st<=dr){
med=(st+dr)/2;
if(legendre(med)>=val){
	dr=med-1;
	last=med;
}
else
	st=med+1;
}
return last;
}
int main()
{
	freopen("fact.in","r",stdin);
	freopen("fact.out","w",stdout);
int n,last;
scanf("%d",&n);
last=bs(0,(1LL<<31)-1,n);
if(last==0)
	printf("1");
else{
if(legendre(last)==n)
printf("%d ",last);
else
	printf("-1");
}
}