Looking at your example code, the .txt file is TAB seperated. You could read it with DBD::CSV if you are slightly acquinted with SQL commands, that might be handy. Here's a start:

use DBI;

my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_dir        => "Results/Classification",
    f_ext        => ".txt/r",

    csv_sep_char => "\t",

    RaiseError   => 1,
    PrintError   => 1,
    }) or die $DBI::errstr;

my $sth = $dbh->prepare ("select max (begin) from classesNormal where 
+nr = 2");
   $sth->execute;
my ($max) = $sth->fetchrow_array;
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