public void Solve()
{
// for now, naively just store values.
var exclude = new HashSet <long>();
long maxCD = 0;
long i = 0;
var e = EValue(0);
while (e > (double)C / 2)
{
if (primes.HaveCommonFactor(C, e, ref maxCD))
{
exclude.Add(e);
}
i += 1;
e = EValue(i);
}
i = 0;
e = EValue(0);
int count = 0;
while (e > (double)C / 2)
{
if (!exclude.Contains(e))
{
count += 1;
}
i += 1;
e = EValue(i);
}
Console.WriteLine($"Count: {2 * count}");
}
