54. Suppose that we want to generate the outcome of the flip of a fair coin but that all we have at our disposal is a biased coin which lands on heads with some unknown probability *p* that need not be equal to 1/2. Consider the following procedure for accomplishing our task.

1. Flip the coin.

2. Flip the coin again.

3. If both flips land heads or both land tails, return to step 1.

4. Let the result of the last flip be the result of the experiment.

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