The data set contains a column with over a 10000 cell phone numbers,it also contains some garbage values with no particular format.
How do I retain only the rows with the correct cell phone numbers
cell number ............ comment
9674544444............... a
9453453455............... c
asd..as23.....................d
as sas E2...................d
232dsasd....................,,,,,,,,,,,,,,,23,,,,,231
required table
cell number ............ comment
9674544444............... a
9453453455............... c