private void Split(FriendsPresents pr, int n, int m)
{
FriendsPresents f1 = pr.Give(n, m);
FriendsPresents f2 = f1.Clone();
Share(f1, n - 1, 0);
Share(f2, n - 1, 1);
}
private void Share(FriendsPresents pr, int n, int m)
{
if (n == 0)
{
pr.Give(n, m);
posibilities.Add(pr);
return;
}
Split(pr, n, m);
}