know a list, ask whether each element in this list is a child of another element, and if so, delete this element.
list = ["GH", "ACDB", "AB", "ABCFE", "ABDCFE", "ACFE", "ABCD", "ABD", "ACBD", "ACD", "FCBA", "FCDBA", "FCA", "FC", "BACF", "BCF", "BDCF", "BACFE", "BCFE", "BDCFE", "BACD", "BCD", "BD", "CBA", "CDBA", "CA", "CAB", "CDB", "CB", "EF", "EFC", "EFCABD", "EFCBD", "EFCD", "DBACF", "DBCF", "DCF", "DBAC", "DBC", "DC"]
as in the above code, the last element that should be left in list is
list=["ABDCFE","GH"]