input is:
A0000.f BG_c22
A000X.f BG_c5
A000X.r BG_c5
A002B.f BG_c38
A002B.r BG_c38
A003A.r BG_c38
A0082.r BG_c12
A00AS.f BG_c52
A00B9.f BG_c45
A00B9.r BG_c45
A00DK.f BG_c5
A00F0.f BG_c22
A00F0.r BG_c22
A00F3.f BG_c14
A00FX.f BG_c7
A00FX.r BG_c7

result shud be:
A0000.f BG_c22
A003A.r BG_c38
A0082.r BG_c12
A00AS.f BG_c52
A00DK.f BG_c5
A00F3.f BG_c14