#include <bits/stdc++.h>
#define ll long long
using namespace std;

ll p;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    ifstream cin("fact.in");
    ofstream cout("fact.out");
    cin>>p;

    if (p==0) cout<<1;
    else
    {
        ll nr=0;
        for (int i=5; i<=1000000000; i+=5)
        {
            ll tmp=i;
            while(tmp%5==0){
                nr++;
                tmp/=5;
            }
            if(nr==p) {
                cout<<i;
                break;

            }
            else if(nr>p){
                cout<<-1;
                break;
            }
        }
    }
    return 0;
}