First numbers that belong to both sets:
12,
34,
45,
54,
56,
65,
76,
78,
87,
98,
210,
212,
232,
234,
321,
323,
345,
432,
434,
454,
456,
543,
545,
565,
654,
656,
676,
678,
765,
767,
789,
876,
878,
898,
987,
989,
1010,
1012,
1210,
1212,
1232,
2101,
2121,
2123,
2321,
2323,
2343,
3210,
3212,
3232,
3234,
3432,
3434,
3454,
4321,
4323,
4343,
4345,
4543,
4545,
4565,
5432,
5434,
5454,
5456,
5654,
5656,
5676,
5678,
6543,
6545,
6565,
6567,
6765,
6767,
6787,
6789,
7654,
7656,
7676,
7678,
7876,
7878,
7898,
8765,
8767,
8787,
8789,
8987,
8989,
9876,
9878,
9898,
10101,
12121,
21010,
21012,
21210,
21212,
21232,
21234,
23210,
23212,
23232,
23234,
23432,
23434,
23454,
32121,
32123,
32343,
34323,
34545,
34565,
34567,
43210,
43212,
43232,
43234,
43432,
43434,
43454,
45432,
45434,
45454,
45456,
45654,
45656,
45676,
45678,
54321,
54343,
54345,
54543,
54545,
54565,
54567,
56545,
56565,
56765,
56787,
56789,
65432,
65434,
65454,
65456,
65654,
65656,
65676,
65678,
67654,
67656,
67676,
67678,
67876,
67878,
67898,
76565,
76567,
76765,
76767,
76787,
76789,
78765,
78767,
78789,
78987,
87654,
87656,
87676,
87678,
87876,
87878,
87898,
89876,
89878,
89898,
98765,
98767,
98787,
98789,
98987,
98989,
101010,
101012,
101210,
101212,
101232,
101234,
121010,
121012,
121210,
121212,
123210,
123212,
123234,
123432,
123454,
210121,
210123,
212101,
212121,
212343,
232101,
232323,
232345,
234321,
234345,
234543,
234565,
234567,
321010,
321012,
321210,
321212,
321232,
321234,
323210,
323212,
323232,
323234,
323432,
323434,
323454,
343210,
343212,
343232,
343234,
343432,
343434,
343454,
343456,
345432,
345434,
345454,
345456,
345654,
345656,
345676,
345678,
432101,
432123,
432321,
432345,
434321,
434343,
434543,
434545,
434565,
454321,
454323,
454343,
454345,
454545,
454565,
454567,
456543,
456565,
456567,
456765,
456787,
456789,
543210,
543212,
543234,
543432,
543434,
543454,
543456,
545432,
545434,
545454,
545456,
545654,
545656,
545676,
545678,
565432,
565434,
565454.
Some larger examples :
9876543,
9876545,
9876565,
9876567,
9876765,
9876767,
9876787,
9876789,
9878765,
9878767,
9878787,
9878789,
9878987,
9878989,
9898765,
9898767,
9898787,
9898789,
9898987,
9898989.