Caesar Cipher

using System;
using System.Text;

public class CaesarCipher
{
    // Encrypts text using a shift od s
    public static StringBuilder encrypt(String text, int s)
    {
        StringBuilder result = new StringBuilder();

        for (int i = 0; i < text.Length; i++)
        {
            if (char.IsUpper(text[i]))
            {
                char ch = (char)(((int)text[i] +
                                s - 65) % 26 + 65);
                result.Append(ch);
            }


            else if (char.IsLower(text[i]))
            {
                char ch = (char)(((int)text[i] +
                                s - 97) % 26 + 97);
                result.Append(ch);
            }
            else if (char.IsSeparator(text[i]))
            {
                char ch = (char)(((int)text[i] +
                    s - 32) % 26 + 32);
                result.Append(ch);
            }
            else if (char.IsPunctuation(text[i]))
            {
                char ch = (char)(((int)text[i] +
                    s - 33) % 26 + 33);
                result.Append(ch);
            }
            else if (char.IsDigit(text[i]))
            {
                char ch = (char)(((int)text[i] +
                    s - 48) % 26 + 48);
                result.Append(ch);
            }


        }
        return result;
    }

    // Driver code
    public static void Main(String[] args)
    {
        String text = Console.ReadLine();
        int s = 3;
        Console.WriteLine(encrypt(text, s));
    }
}