level step 0.00390625: 341 (a,b) boxes
  0/341  4s  bad so far 0
  200/341  31s  bad so far 27
level step 0.001953125: 333 (a,b) boxes
  0/333  51s  bad so far 0
  200/333  78s  bad so far 3
level step 0.0009765625: 12 (a,b) boxes
  0/12  95s  bad so far 0
{"part": "B", "levels": [{"step": 0.00390625, "nboxes": 341, "nbad": 85, "lam_m_boxes": 1014400}, {"step": 0.001953125, "nboxes": 333, "nbad": 3, "lam_m_boxes": 314008}, {"step": 0.0009765625, "nboxes": 12, "nbad": 0, "lam_m_boxes": 10820}], "certified": 598, "sec": 95.06369757652283}
