use strict;
open(OFILE,">output.txt") or die "Unable to open output file";
open(IFILE,"<input.txt") or die "Unable to open input file";
while ( <IFILE>)
{
print OFILE  unless /^CPXX1|^KLXX1|^KMXX1|^MEXX1|^PAXX1|^PMXX1|^SLXX1|^SZXX1|^WXXX1|^YZXX1/
}
close(IFILE);
close(OFILE);