String decompression with nested parentheses and repetition counts

Problem Implement a string decompression function decompress(s: str) -> str. The input contains: lowercase letters a-z parentheses ( and ) denoting a subexpression braces {} that appear immediately after a right parenthesis ) to indicate repeating the parenthesized subexpression Rules: X(Y){k} means output X followed by Y repeated k times. Parentheses may be nested. k is in [2, 99]. The input is guaranteed valid (no need to handle malformed parentheses/braces), and { always appears after the matching ). Examples: "a(abc){3}" -> "aabcabcabc" "a(b(c){2}){3}d" -> "abccbccbccd" Constraints 1 <= len(s) <= 2 * 10^5 Output may be large; generating the full string is acceptable unless it exceeds memory (you may mention streaming as an optimization). Task Return the decompressed string. Example Input a(abc){3} Output aabcabcabc