c#获取多个List<class>合并、并将相同条件下的值累计sum

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<strudent> one = new List<strudent>();
            one.Add(new strudent() { age = , name = "aaa" });
            one.Add(new strudent() { age = , name = "bbb" });
            one.Add(new strudent() { age = , name = "ddd" });
            one.Add(new strudent() { age = , name = "fff" });
            one.Add(new strudent() { age = , name = "ggg" });
            one.Add(new strudent() { age = , name = "eee" });
            List<strudent> two = new List<strudent>();
            two.Add(new strudent() { age = , name = "aaa" });
            two.Add(new strudent() { age = , name = "bbb" });
            two.Add(new strudent() { age = , name = "ddd" });
            two.Add(new strudent() { age = , name = "fff" });
            two.Add(new strudent() { age = , name = "ggg" });
            two.Add(new strudent() { age = , name = "eee" });
            two.Add(new strudent() { age = , name = "aaaaa" });
            var tt = one.Union(two).ToList();
            var res = from p in tt
                      group p by new { p.name } into g
                      select new { name = g.Key.name, accp = g.Sum(p => p.age) };

            tt.ForEach(x =>
            {
                Console.WriteLine(x.name + "     " + x.age);
            });
            Console.ReadKey();
        }
    }

    public class strudent
    {
        public decimal age { get; set; }
        public string name { get; set; }
    }
    public class StudentListEquality : IEqualityComparer<strudent>
    {
        public bool Equals(strudent x, strudent y)
        {
            return x.name == y.name;
        }
        public decimal sum(strudent x, strudent y)
        {
            if (x.name == y.name)
            {
                return x.age + y.age;
            }
            return ;
        }
        public int GetHashCode(strudent obj)
        {
            if (obj == null)
            {
                return ;
            }
            else
            {
                return obj.ToString().GetHashCode();
            }
        }
    }

}