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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def merkle_pair(hashes, hash_f):
 """Take a list of hashes, and return the parent row in the tree of merkle hashes."""

    if len(hashes) % 2 == 1:
        hashes = list(hashes)
        hashes.append(hashes[-1])
    items = []
    for i in range(0, len(hashes), 2):
        items.append(hash_f(hashes[i] + hashes[i+1]))
    return items