diff --git a/unit05_key_exchange/src/e_01.py b/unit05_key_exchange/src/e_01.py
index 65afc9d..c9e2d5d 100644
--- a/unit05_key_exchange/src/e_01.py
+++ b/unit05_key_exchange/src/e_01.py
@@ -34,8 +34,8 @@ rnd = random.randint(1,2**128)
 
 keyB= hashlib.md5(str(rnd)).digest()
  
-print 'Long-term Key Alice=',binascii.hexlify(keyA)
-print 'Long-term Key Bob=',binascii.hexlify(keyB)
+print ('Long-term Key Alice=',binascii.hexlify(keyA))
+print ('Long-term Key Bob=',binascii.hexlify(keyB))
 
 rnd = random.randint(1,2**128)
 keySession= hashlib.md5(str(rnd)).hexdigest()
@@ -43,11 +43,11 @@ keySession= hashlib.md5(str(rnd)).hexdigest()
 ya = encrypt(keySession,keyA,AES.MODE_ECB)
 yb = encrypt(keySession,keyB,AES.MODE_ECB)
 
-print "Encrypted key sent to Alice:",binascii.hexlify(ya)
-print "Encrypted key sent to Bob:",binascii.hexlify(yb)
+print ("Encrypted key sent to Alice:",binascii.hexlify(ya))
+print ("Encrypted key sent to Bob:",binascii.hexlify(yb))
 
 decipherA = decrypt(ya,keyA,AES.MODE_ECB)
 decipherB = decrypt(yb,keyB,AES.MODE_ECB)
 
-print "Session key:",decipherA
-print "Session key:",decipherB
+print ("Session key:",decipherA)
+print ("Session key:",decipherB)