Find the longest sequence of “1”s.?

Question

Given an array:
  [\'1\', \'1\', \'1\', \'1\', \'1\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'0\', \'1\'