#include<fstream.h>
ifstream f("fact.in");
ofstream g("fact.out");
int main()
{long n,p,nr=0,i;
f>>p;
if(p==0) g<<1;
else for(n=1;n<=500000;n++)
{i=n;while(i%5==0) {nr++;i=i/5;}
if(nr==p) {g<<n;n=500001; }
}if(n==500000) g<<-1;
return 0;

}