The first dangle is combined with the nucleotide within parentheses, represented as "X)X" or "X(X", numbered from 17.1 to 24.4. Other dangles combined with "*", represented as "*X", numbered from 25 to 28. There are 36 dangles in total. 3) Loop: nucleotides outside of parentheses and terminated by "(" or ")", represented as "X", numbered from 29 to 32. 4) Initiation: The first and last nucleotides in the stacks or the nick between strands, represented as "(X", "X)", or ".", numbered from 33 to 41.