Delete unwanted lines
Delete all lines which does not end in "o.."
gamag gamah ganci gaoag gaoah gaoci gbmag gboch gboci gcmag gcmah gcmai gcnci gcoag gcoah gcoai gcoch gcobg gcoci hamag hamah hanci haoag hbmag hbnci hboag hboch hboci hcmag hcncg hcnch hcnci hcoag hcoci iamag
gaoag gaoah gaoci gboch gboci gcoag gcoah gcoai gcoch gcobg gcoci haoag hboag hboch hboci hcoag hcoci