Consider the following code segment:

a = int(input("Enter an integer: "))
b = int(input("Enter an integer: "))
if a <= 0:
   b = b +1
else:
   a = a + 1
if a > 0 and b > 0: 
   print ("W") 
elif a > 0:
   print("X") 
if b > 0:
   print("Y") 
else:
   print("Z")

What letters will be printed if the user enters -1 for a and -1 for b?