python programming help?

i tryed to make sometime that inputs a number then tells me which one is the largest and smallest:
A= raw_input("Enter your list of numbers, seperated by commas-> ")
B= max(A)
C= min(A)
print "The largest number is ->", B
print "The smallest number is ->", C


but how come the largest value can't be over 9 and the smallest value comes out to be ","?