属于这两组的第一个数字：
21,23,34,45,54,56,65,78,87,101,210,212,323,343,434,454,543,565,567,654,656,678,765,767,789,876,878,987,989,1012,1212,1232,2101,2343,3434,3454,3456,4343,4543,4545,4565,4567,5432,5454,5456,5654,5656,5676,5678,6543,6545,6565,6567,6765,6767,6789,7654,7676,7678,7878,8765,8767,8789,8989,9876,9878,10101,12101,12121,12343,21012,21212,21232,23234,23454,32101,32343,34321,34343,34543,34565,34567,43232,43454,43456,45432,45454,45654,45656,45678,54343,54543,54565,54567,56543,56565,56567,56765,56767,56789,65432,65454,65654,65656,65676,65678,67654,67676,67678,67878,76543,76565,76567,76765,76767,76787,76789,78765,78767,78789,78989,87654,87676,87678,87878,89876,89878,98765,98767,98789,98987,98989,101010,101012,101212,101232,121012,121212,123232,123234,123454,210101,212101,212343,232101,232343,234343,234543,234565,234567,321012,321212,321232,323454,323456,343210,343434,343454,345432,345454,345456,345654,345656,345678,432101,432123,432343,434343,434543,434545,434565,434567,454343,454543,454565,454567,456543,456565,456567,456765,456767,456789,543454,543456,545432,545454,545654,545656,545678,565432,565454,565456,565654,565656,565678,567654,567676,567678,567878,654343,654543,654545,654565,654567,656543,656565,656567,656765,656767,656789,676543,676545,676565,676567,676765,676767,676789,678765,678767,678789,678987,678989,765432,765454,765654,765656,765678,767654,767676,767678,767878,787654,787676,787678,787878,789876,789878,876543,876565,876567,876765,876767,876789,878765,878767,878789,878989,898765,898767,898789,898989,987654,987676,987678,987878,989876,989878,1010101,1012101,1012343,1210101,1210121,1212101,1212321,1212343,1232101,1232343,1234343,1234543,1234565,1234567,2101012,2101212,2101232,2101234,2121012,2121210,2121212,2123210,2123232. 一些较大的示例：
8987654,8987676,8987678,8987878,8989876,8989878,9876543,9876565,9876567,9876765,9876767,9876789,9878765,9878767,9878789,9878989,9898765,9898767,9898789,9898989.