using System;

public class Test
{
	public static void Main()
	{
		String plainAlphabet = "abcdefghijklmnopqrstuvwxyz";
		String cipherAlphabet = "zyxwvutsrqponmlkjihgfedcba";
		String text = "Some sensitive text that only humans must be able to read";
 
		String encodedText = encrypt(plainAlphabet, cipherAlphabet, text);
		Console.WriteLine(encodedText);
	}
	
	public static String encrypt(String plain, String cipher, String text) {
	    plain = plain + plain.ToUpper();
	    cipher = cipher + cipher.ToUpper();
	 
	    String newText = "";
	    for(int i=0; i<text.Length; i++) {
	        char c = text[i];
	        int index = plain.IndexOf(c);
	        if(index >= 0 && index < cipher.Length) {
	            newText += cipher[index];
	        } else {
	            newText += c;
	        }
	    }
	    return newText;
	}
}