I have a file text with multilines with the same begin words, example: A: 23823-11212-35662 B: aBcjdjLJ C: 9o9j0l D: 990pln
A:76867-35624-63524 B: RtGhTbjO C: 775ply D: 452GNr
...
I only need text follow "A:" Please help me. Thanks.