!7

p {
  assertEqualsVerbose(0, detectListInsertion(ll(), ll()).length());
  assertEqualsVerbose(0, detectListInsertion(ll("a"), ll("a")).length());
  assertEqualsVerbose(intRange(0, 1), detectListInsertion(ll(), ll("a"));
  assertEqualsVerbose(intRange(1, 2), detectListInsertion(ll("a", "c"), ll("a", "b", "c")));
  assertNull(detectListInsertion(ll("a", "c"), ll("a", "b", "d")));
  assertNull(detectListInsertion(ll("a"), ll()));
  print("OK");
}