 let alphaUpperCount = alphaUpper.characters.count
 
 let input = "Nearly all men can stand adversity, but if you want to test a man's character, give him power."
-let shiftValue = 8
+let shiftValue = 13
 var encrypted = ""
 var decrypted = ""
 var encrypting = true

 
 **Constraints:**
 - The encrypted and decrypted text is case sensitive
 - Add a shift variable to indicate how many places to shift
 */
import Foundation


        var advancedBy: Int
        if encrypting {
            distance = alphaCount - alpha.distance(from: found.lowerBound, to: alpha.endIndex)
            advancedBy = (distance + (shiftValue == Int.max ? (shiftValue - distance) : shiftValue)) % alphaCount
        } else {
            distance = alpha.characters.distance(from: alpha.startIndex, to: found.lowerBound)
            advancedBy = (distance - shiftValue) % alphaCount
