Solve the problem with decomposition and self-verification. For each reasoning step, you MUST decompose its internal logic into substeps, verify each substep, and combine the substep results to confirm or reject the step before proceeding.

FORMAT RULES (follow exactly):
- Label each reasoning step as [R1], [R2], etc.
- After writing [Rn], DECOMPOSE that step's logic into atomic substeps:
  - [Rn-D1], [Rn-D2], etc. — each substep isolates one assumption, one retrieval, or one micro-operation that [Rn] depends on.
- VERIFY each substep independently:
  - [Rn-V1], [Rn-V2], etc. — check whether each substep is correct. End each with PASS or FAIL.
CRITICAL VERIFICATION RULE::
A reasoning step is valid only if every logical constraint is explicitly derived from previous steps.
Treat unsupported intermediate values as invalid unless justified by earlier steps.
- COMBINE substep verdicts into an overall verdict for the step:
  - [Rn-Combine]: summarize substep results and state whether [Rn] holds. End with PASS or FAIL.
- If FAIL: redo the step as [Rn'], decompose and verify again.
- You may retry a step at most 2 times.
- Only move to [R(n+1)] after the current step passes.

OUTPUT FORMAT:
[Question]: <restate the question>

[R1]: <first reasoning step>
  [R1-D1]: <substep 1 — one atomic piece of logic R1 depends on>
  [R1-V1]: <verify substep 1> → PASS or FAIL
  [R1-D2]: <substep 2>
  [R1-V2]: <verify substep 2> → PASS or FAIL
  [R1-Combine]: <all substeps pass? → overall verdict for R1> → PASS or FAIL

[R2]: <second reasoning step>
  [R2-D1]: <substep 1>
  [R2-V1]: <verify substep 1> → PASS or FAIL
  ...
  [R2-Combine]: → PASS or FAIL

...

[Rn]: <final reasoning step>
  [Rn-D1]: ...
  [Rn-V1]: ...
  [Rn-Combine]: → PASS or FAIL

[Answer]: <your final answer>

EXAMPLE:
[Question]: A store offers 20% off, then an additional 15% off the discounted price. What is the total percentage discount on a $200 item?

[R1]: Apply first discount: $200 × 0.20 = $40 off, price becomes $160.
  [R1-D1]: The first discount rate is 20%, applied to the original price $200.
  [R1-V1]: Given directly in the problem. → PASS
  [R1-D2]: 20% of $200 = $200 × 0.20 = $40.
  [R1-V2]: 200 × 0.2 = 40. Correct. → PASS
  [R1-D3]: Discounted price = $200 - $40 = $160.
  [R1-V3]: 200 - 40 = 160. Correct. → PASS
  [R1-Combine]: All substeps pass. R1 is valid. → PASS

[R2]: Apply second discount: $160 × 0.15 = $24 off, price becomes $136.
  [R2-D1]: The second discount is 15%, applied to the already-discounted price $160 (not the original $200).
  [R2-V1]: Problem says "additional 15% off the discounted price." Confirmed: base is $160. → PASS
  [R2-D2]: 15% of $160 = $160 × 0.15 = $24.
  [R2-V2]: 160 × 0.15 = 24. Correct. → PASS
  [R2-D3]: Final price = $160 - $24 = $136.
  [R2-V3]: 160 - 24 = 136. Correct. → PASS
  [R2-Combine]: All substeps pass. R2 is valid. → PASS

[R3]: Total discount = $200 - $136 = $74. Percentage = 74 / 200 = 37%.
  [R3-D1]: Total dollar discount = original price - final price = $200 - $136.
  [R3-V1]: 200 - 136 = 64, not 74. → FAIL
  [R3-Combine]: Substep 1 failed. R3 is invalid. → FAIL

[R3']: Total discount = $200 - $136 = $64. Percentage = 64 / 200 = 32%.
  [R3'-D1]: Total dollar discount = $200 - $136 = $64.
  [R3'-V1]: 200 - 136 = 64. Correct. → PASS
  [R3'-D2]: Percentage discount = $64 / $200 = 0.32 = 32%.
  [R3'-V2]: 64 / 200 = 0.32 = 32%. Correct. → PASS
  [R3'-Combine]: All substeps pass. R3' is valid. → PASS

[Answer]: The total discount is 32%.

Now solve:
{question}
