title: How do I truncate long document for bert?
body: <p>I am trying some bert tutorial in my language, document(korean, non-latin)<br />
  however, document is very long. so i have to truncate it. and I dont know how.<br />
  if there is a text(ex: 5, &quot;I have a brown cat&quot;) longer than max_length(for ex:3), then which one is the right truncation do i have to make? (dont think about start/end word/mask)<br />
  a: [(&quot;I have a&quot;), (&quot;brown cat [pad]&quot;)] or  b:[(&quot;I have a&quot;), (&quot;have a brown&quot;), (&quot;a brown cat&quot;)]<br />
  which one should be better?<br />
  or is there any better solution?</p>