Decrypt number

Given a non-empty string consisting only of special chars (!, @, # etc.), return a number (as a string) where each digit corresponds to given special char on the keyboard ( 1→ !, 2 → @, 3 → # etc.).
Expected input and output
"())(" → "9009" "*$(#&" → "84937" "!!!!!!!!!!" → "1111111111"
using System;
using System.Linq;

namespace CSharpExercises.Exercises.LINQ
{
    class DecryptNumberTask
    {
        public static void Main()
        {
            var chars = new char[] { ')', '!', '@', '#', '$', '%', '^', '&', '*', '(' };

            var encryptedNumber = "#(@*%)$(&$*#&";

            var decryptedNumber = string.Join("", encryptedNumber.Select(c => Array.IndexOf(chars, c)));

            Console.WriteLine(decryptedNumber); // 3928504974837
        }
    }
}