static ImmutableQueue <int> MakeQueue(System.Collections.Generic.IEnumerable <int> e) => e.Aggregate(ImmutableQueue <int> .Empty, (q, item) => q.Enqueue(item));
static ImmutableQueue <int> MakeQueue(System.Collections.Generic.IEnumerable <int> e) => e.Aggregate(ImmutableQueue <int> .Empty, (q, item) => q.Enqueue(item));