def classify(op):
    """
    Given an operation name, decide whether it is a constructor or
    an annihilator.  The convention is that constructors are operations
    starting with 'c', and all other operations are annihilators.

    >>> classify("c")
    'C'

    >>> classify("c2df")
    'C'

    >>> classify("a")
    'A'

    >>> classify("h")
    'A'

    """

    if op[0] is 'c':
        return 'C'
    else:
        return 'A'