#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fact.in");
ofstream g("fact.out");
int main()
{   unsigned long long n,i,p=1,d=0,c=0,j,d1,c1,k=0;
    f>>n;
    if(n==0) g<<"1";
    else
        {for(i=2;k<n;i++)
            {d1=0;j=i;
            c1=0;
            while(j%2==0)
                {d1++;
                j/=2;
                }
            while(j%5==0)
                {c1++;
                j/=5;
                }
            d+=d1; c+=c1;
            if(d>c)
                k=c;
            else
                k=d;
            if(k==n)
                g<<i;
            else if(k>n)
                g<<"-1";
            }
        }
    f.close();
    g.close();
    return 0;
}