use strict;
use warnings;

use 5.010;

use Data::Dumper;

open my $lookFH, q{<}, \ <<EOD or die qq{open: << HEREDOC: $!\n};
20
30
50
EOD

chomp( my @lookFor = <$lookFH> );
my $lookForRE = do{
   local $" = q{|};
   qr{^(@lookFor)\s+(\d+)}
   };

my %accumulate;

open my $nosFH, q{<}, \ <<EOD or die qq{open: << HEREDOC: $!\n};
10 23432
20 23424
60 45567
20 56756
30 91857
50 29349
10 93729
80 82374
20 82757
30 92785
50 71674
70 81747
20 83758
30 89275
10 19594
60 09214
20 09347
50 83725
90 91845
20 76402
30 90184
EOD

while ( <$nosFH> )
{
    next unless m{$lookForRE};
    chomp;
    push @{ $accumulate{ $1 }->{ lines } }, $_;
    $accumulate{ $1 }->{ sum } += $2;
}

foreach my $group ( @lookFor )
{
    say join q{ },
       $_,
       $accumulate{ $group }->{ sum }
       for @{ $accumulate{ $group }->{ lines } }
}

print Data::Dumper->Dumpxs(
  [ \ %accumulate ],
  [ qw{ *accumulate } ]
  );

##</code><code>##

20 23424 332444
20 56756 332444
20 82757 332444
20 83758 332444
20 09347 332444
20 76402 332444
30 91857 364101
30 92785 364101
30 89275 364101
30 90184 364101
50 29349 184748
50 71674 184748
50 83725 184748
%accumulate = (
                '50' => {
                          'lines' => [
                                       '50 29349',
                                       '50 71674',
                                       '50 83725'
                                     ],
                          'sum' => '184748'
                        },
                '30' => {
                          'lines' => [
                                       '30 91857',
                                       '30 92785',
                                       '30 89275',
                                       '30 90184'
                                     ],
                          'sum' => '364101'
                        },
                '20' => {
                          'lines' => [
                                       '20 23424',
                                       '20 56756',
                                       '20 82757',
                                       '20 83758',
                                       '20 09347',
                                       '20 76402'
                                     ],
                          'sum' => '332444'
                        }
              );