Using counter() with ordinary descendant <ol> elements

1. first
2. second
3. third
   1. third,one
   2. third,two
      1. third,two,one
      2. third,two,two
         1. third,two,two,one
         2. third,two,two,two
      3. third,two,three
   3. third,three
4. fourth
   1. fourth,one

New Instance

1. fifth
2. sixth