using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main(string[] args)

    {

        Dictionary<char, decimal> Letters = new Dictionary<char, decimal>()

        {{'A', 1.5m}, {'C', 3.9m}, {'R', 3.1m}, };

        string input = "CAR";

        decimal result = input.Where(x => Letters.ContainsKey(x)).Sum(x => Letters[x]);

        Console.Write(result);

    }

}