LINQ, How to decompose a list into three maximally equal lists?

Question

C++ / C#

Initial data - a list of arbitrary length
L123 list (1, 5, 7, 3, 2, 9, 1)
Goal - decompose as evenly as possible into three lists
L1, L2, L3
Algorithm
Sort L123 in descending order L123 list (9 ,7, 5, 3, 2, 1, 1)
We look for the sum L1, L2, L3 and add the first element L123 to any minimal list, and so on.
Outcome L1(9); L2(7, 2); L3(5, 3, 1, 1)
How to implement this in LINQ?

Answer 1

Thank you. to everyone who was interested.
Decided everything myself)

List<List<double>> L123 = new List<List<double>> { new List<double>(), new List<double>(), new List<double>() };
            new List<double>() { 1, 1, 2, 3, 5, 7, 9 }
               .OrderByDescending(a => a)
               .ToList()
               .ForEach(b =>
               {
                   L123
                  .ElementAt(L123
                            .Select((e, i) => new { e, i })
                            .Aggregate((f, s) => f.e.Sum() < s.e.Sum() ? f : s)
                            .i)
                  .Add(b);
               });