#include <iostream>
#include <fstream>

using namespace std;
int n,p,c;

ifstream fin("fact.in");
ofstream fout("fact.out");

int main()
{
    fin>>p;
    n=0;
    c=0;
    while (c<p)
    {
        n=n+5;
        if (n%25==0) c=c+2;
        else c++;
    }
    if (p==0) fout<<1;
    else if (c==p) fout<<n;
    else fout<<-1;
}