#include <fstream>
using namespace std;
ifstream cin ("fact.in");
ofstream cout ("fact.out");
int nz(int x){
    int cnt2=0,cnt5=0;
    for(int i=1;i<=x;i++){
            int aux=i;
    while(aux%2==0)
        cnt2++,aux/=2;
    while(aux%5==0)
        cnt5++,aux/=5;
    }
        return min(cnt2,cnt5);
}
unsigned long long cautarebinara(int x){
    if(x==0)
        return 1;
    unsigned long long st=0,dr=100000001;
int res=-1;
    while(st<=dr){
        int mij=(st+dr)/2;
        if(nz(mij)==x){
            res=mij;
        dr=mij-1;
            }
        else if(nz(mij)>x)
            dr=mij-1;
        else
            st=mij+1;
    }
    return res;
}
int main()
{
    unsigned long long x;
    while(cin>>x){
        cout<<cautarebinara(x)<<" ";
    }
    return 0;
}