#include<stdio.h>
#define N 100000001
int main()
{int h=1,i,j,p,nr=0;
freopen("fact.in", "r",stdin);
freopen("fact.out", "w",stdout);
scanf("%d", &p);
if(p>=1000000) {nr=1000000; h=4000005;}
if(p>=10000000){nr=10000000; h=40000010;}
if(p>=50000000) {nr=50000000; h=100000001;}

	for(i=h;i<=N;++i) 
	   {if(nr==p) break;
		   if(i%5==0) { j=i; while(j%5==0) {j=j/5; ++nr;}} 	
			if(nr==p) break; if(nr>p) {i=-1; break;}
        	
	   }
	printf("%d", i);
return 0;
}