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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 R(X, destination, a1, a2, b):
 """A single Salsa20 row operation"""


    a = (X[a1] + X[a2]) & 0xffffffff
    X[destination] ^= ((a << b) | (a >> (32 - b)))