[routing-wg] Looking for a pgm to CIDRize

Dear revelers, I am looking for a program or website that can take a list of sorted, overlapping prefixes and can reduce it to the most CIDRized format. Example: 5.28.128.0/18 5.28.128.0/20 5.28.128.0/21 5.28.128.0/22 5.28.132.0/23 5.28.136.0/21 5.28.136.0/22 5.29.64.0/18 5.29.64.0/20 5.29.80.0/24 5.29.96.0/20 would reduce to just 2 lines: 5.28.128.0/18 5.29.64.0/18 In the long distant past, I seem to remember hearing or seeing of such a program. Any pointers would be appreciated. Happy New Year, Hank