First numbers that belong to both sets:
5,
55,
64,
73,
82,
91,
555,
654,
753,
852,
951,
5555,
6554,
6644,
7553,
7643,
7733,
8552,
8642,
8732,
8822,
9551,
9641,
9731,
9821,
9911,
55555,
65554,
66544,
75553,
76543,
77533,
85552,
86542,
87532,
88522,
95551,
96541,
97531,
98521,
99511,
555555,
655554,
665544,
666444,
755553,
765543,
766443,
775533,
776433,
777333,
855552,
865542,
866442,
875532,
876432,
877332,
885522,
886422,
887322,
888222,
955551,
965541,
966441,
975531,
976431,
977331,
985521,
986421,
987321,
988221,
995511,
996411,
997311,
998211,
999111,
5555555,
6555554,
6655544,
6665444,
7555553,
7655543,
7665443,
7755533,
7765433,
7775333,
8555552,
8655542,
8665442,
8755532,
8765432,
8775332,
8855522,
8865422,
8875322,
8885222,
9555551,
9655541,
9665441,
9755531,
9765431,
9775331,
9855521,
9865421,
9875321,
9885221,
9955511,
9965411,
9975311,
9985211,
9995111,
55555555,
65555554,
66555544,
66655444,
66664444,
75555553,
76555543,
76655443,
76664443,
77555533,
77655433,
77664433,
77755333,
77764333,
77773333,
85555552,
86555542,
86655442,
86664442,
87555532,
87655432,
87664432,
87755332,
87764332,
87773332,
88555522,
88655422,
88664422,
88755322,
88764322,
88773322,
88855222,
88864222,
88873222,
88882222,
95555551,
96555541,
96655441,
96664441,
97555531,
97655431,
97664431,
97755331,
97764331,
97773331,
98555521,
98655421,
98664421,
98755321,
98764321,
98773321,
98855221,
98864221,
98873221,
98882221,
99555511,
99655411,
99664411,
99755311,
99764311,
99773311,
99855211,
99864211,
99873211,
99882211,
99955111,
99964111,
99973111,
99982111,
99991111,
555555555,
655555554,
665555544,
666555444,
666654444,
755555553,
765555543,
766555443,
766654443,
775555533,
776555433,
776654433,
777555333,
777654333,
777753333,
855555552,
865555542,
866555442,
866654442,
875555532,
876555432,
876654432,
877555332,
877654332,
877753332,
885555522,
886555422,
886654422,
887555322,
887654322,
887753322,
888555222,
888654222,
888753222,
888852222,
955555551,
965555541,
966555441,
966654441,
975555531,
976555431,
976654431,
977555331,
977654331,
977753331,
985555521,
986555421,
986654421,
987555321,
987654321,
987753321,
988555221,
988654221,
988753221,
988852221,
995555511,
996555411,
996654411,
997555311,
997654311,
997753311,
998555211,
998654211,
998753211,
998852211,
999555111,
999654111,
999753111,
999852111,
999951111,
5555555555,
6555555554,
6655555544,
6665555444,
6666554444,
6666644444,
7555555553,
7655555543,
7665555443,
7666554443,
7666644443,
7755555533,
7765555433,
7766554433,
7766644433,
7775555333,
7776554333,
7776644333,
7777553333,
7777643333,
7777733333,
8555555552,
8655555542,
8665555442,
8666554442,
8666644442,
8755555532,
8765555432,
8766554432.
Some larger examples :
999987753321111,
999988555221111,
999988654221111,
999988753221111,
999988852221111,
999995555511111,
999996555411111,
999996654411111,
999997555311111,
999997654311111,
999997753311111,
999998555211111,
999998654211111,
999998753211111,
999998852211111,
999999555111111,
999999654111111,
999999753111111,
999999852111111,
999999951111111.