#include<iostream>
#include<fstream>
using namespace std;
const int dim=100000000;
int n,p,i,j,v[dim];
ifstream in("fact.in");
ofstream out("fact.out");


void rez(){int nr=0;
v[0]=1;
for(i=1;i<=p;i++)
{if(v[i]%5==0){
j=i;
while(j){
    if(j%5==0)j/=5,nr++;
    else break;
}j=i;i+=nr;
v[i]=j*5;
}
   else
        {v[i]=j*5;nr=0;}
//if(nr!=0)j=i-nr+1;
//else j=i;
}

/*for(i=1;i<=p;i++)
    cout<<v[i]<<" ";*/


if(v[p]!=0)out<<v[p];
else out<<-1;

}

int main(){
in>>p;
rez();

in.close();
out.close();
return 0;}