import sys
def encrypt(strng, key):
 encrypted = ''
 for x in strng:
 indx = (ord(x) + key) % 256
 if indx > 126:
 indx = indx - 95
 encrypted = encrypted + chr(indx)
 return encrypted


def decrypt(strng, key):
 decrypted = ''
 for x in strng:
 indx = (ord(x) - key) % 256
 if indx < 32:
 indx = indx + 95
 decrypted = decrypted + chr(indx)
 return decrypted

def brute_force(strng):
 key = 1
 decrypted = ''
 while key <= 94:
 for x in strng:
 indx = (ord(x) - key) % 256
 if indx < 32:
 indx = indx + 95
 decrypted = decrypted + chr(indx)
 print("Key: {}\t| Message: {}".format(key, decrypted))
 decrypted = ''
 key += 1
 return None


def main():
 while True:
 print('-' * 10 + "\n**Menu**\n" + '-' * 10)
 print("1.Encrpyt")
 print("2.Decrypt")
 print("3.BruteForce")
 print("4.Quit")
 choice = input("What would you like to do?: ")
 if choice not in ['1', '2', '3', '4']:
 print ("Invalid choice, please enter a valid choice")
 elif choice == '1':
 strng = input("Please enter the string to be encrypted: ")
 key = int(input("Please enter off-set between 1-94: "))
 if key in range(1, 95):
 print (encrypt(strng.lower(), key))
 elif choice == '2':
 strng = input("Please enter the string to be decrypted: ")
 key = int(input("Please enter off-set between 1-94: "))
 if key in range(1,95):
 print(decrypt(strng, key))
 elif choice == '3':
 strng = input("Please enter the string to be decrypted: ")
 brute_force(strng)
 main()
 elif choice == '4':
 print ("Goodbye.")
 break
main()