{
  "observed_masks": 12,
  "source_proof_sha256": "dc6ff76e3544449855871cfc219dbaa66edb94c4daf62afa9e20a67f727b7b1d",
  "manual": "https://c64online.com/wp-content/uploads/2021/03/Impossible-Mission.pdf",
  "rule": "Same color; any two pieces without overlapping opaque pixels can combine. Four pieces per solution; nonoverlap alone does not prove common puzzle membership.",
  "best_overlap_ranked": [
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      "overlap": 8,
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      "overlap": 8,
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    {
      "overlap": 10,
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      "flips": [
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    },
    {
      "overlap": 10,
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    },
    {
      "overlap": 10,
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    },
    {
      "overlap": 10,
      "union": 309,
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    },
    {
      "overlap": 10,
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        11
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    },
    {
      "overlap": 10,
      "union": 296,
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        1
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    },
    {
      "overlap": 10,
      "union": 296,
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        9,
        10,
        11
      ],
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        2
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    },
    {
      "overlap": 10,
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  "orientation_encoding": [
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  "no_password_letter_inferred": true
}