1  Regexp: ((a|b|\p{Nd}){1,2}|aaa|bbbb){1,2}
 2  bab: Ok
 3  aaca: Fail
 4  aaabbbb: Ok
 5  a0b: Ok
 6  aa0aaa: Fail
 7  b0aaa: Ok
 8  Regexp: (\d{1,3}\.){3}\d{1,3}
 9  1.2.3.4: Ok
10  1.22.333.44: Ok
11  1.2.3: Fail
12  1..2.3: Fail