pr22.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Euler
{
    static void Main(string[] args) => Console.WriteLine(
        File.ReadAllText("./p022_names.txt")
            .Replace("\"", "")
            .Split(',')
            .OrderBy(n => n)
            .Select((n, i) => n.Select(c => (int)c - 64).Sum() * (i+1))
            .MySum()
    );
}

static class Extensions
{
     public static int MySum(this IEnumerable<int> ns) => ns.Aggregate((x, y) => x + y);
}