Python integer conversion program error question

sel=int("Determine input number (16/10/8/2) :")

if sel != 16 or 10 or 8 or 2:
     print ("Error")

if sel == 16 or 10 or 8 or 2:
     num=input ("Enter Value:")

if sel == 16 :
     num10 = int(num,16)
if sel == 10 :
     num10 = int(num,10)
if sel == 8 :
     num10 = int(num,8)
if sel == 2 :
     num10 = int(num,2)

print ("hex==>", hex(num10))
print("decimal==>", num10)
print("Hex ==>", oct(num10))
print("Binary ==>",bin(num10))