I have output from a program that looks like this 
# Output from 'compseq'
#
# The Expected frequencies are calculated on the (false) assumption th
+at every
# word has equal frequency.
#
# The input sequences are:
#       2L


Word size       1
Total count     48795086

#
# Word  Obs Count       Obs Frequency   Exp Frequency   Obs/Exp Freque
+ncy
#
A       13340410                0.2733966       0.2500000       1.0935
+864
C       10686861                0.2190151       0.2500000       0.8760
+604
G       10692025                0.2191209       0.2500000       0.8764
+838
T       13352116                0.2736365       0.2500000       1.0945
+460

Other   723674          0.0148309       0.0000000       10000000000.00
+00000

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Sometimes the Other   ... line can be missing, and the output ends with the T .... line. I'm trying to extract four values from this:
(1) The value next to Total count
(2) The first column next to G
(3) The first column next to C
(4) The first column next to Other, if it exists.
My regular exprn looks like this: 
     $compseqOutput =~ m/Total\scount\s+(\d+).+?
                     C\s+(\d+).+?
                  G\s+(\d+).+?
                 (?:Other\s+(\d+))?/sx

[download]
, where I'm trying to allow for the fact the Other... line might not be found in $compseqOutput. For some reason, it fails when I have this -- it works perfectly when the expression is 
     $compseqOutput =~ m/Total\scount\s+(\d+).+?
                     C\s+(\d+).+?
                  G\s+(\d+).+?
                 Other\s+(\d+)/sx

[download]
, but obviously that doesnt do what I want it to. I know I can get around this in many ways, but why does this not work?

In reply to Regular Expn Problem by venkatr_n

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