Step 1: Identify Open Parentheses. Scan the input string and identify all types of open parentheses: '(', '{', '[', '<'.

Step 2: Match and Close Parentheses.For each open parenthesis, find the corresponding closing parenthesis: ')', '}', ']', '>'.
Ensure that the parentheses are closed in the correct order, matching the most recently opened parenthesis first.

Step 3: Build the Closing Sequence. Create a sequence of closing parentheses that correctly matches and closes each open parenthesis in the input.

Step 4: Maintain Order and Balance. Ensure that the closing sequence maintains the order and balance of parentheses, brackets, and braces as per the Dyck language rules.

Step 5: Output the Completed Sequence. Generate the input sequence concatenated with the generated closing sequence of parentheses, ensuring a well-formed structure.