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open(A,"<$file_a") or die "I cannot open $file_a to read\n";
open(B,"<$file_b") or die "I cannot open $file_b to read\n";
@a=<A>;
@b=<B>;
close(A);
close(B);
foreach my $line (@a)
    {
    chomp($line);
    push(@new,$line);
    if ($line=~m/\*{3} Initial Temperature/)
        {
        foreach my $line (@b)
            {
            chomp($line);
            push(@new,$line);
            }
        }
    }
open (NEW,">$file_a") or die "I cannot open $file_a to write\n";
foreach my $line (@new)
    {
    print NEW "$line\n";
    }
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