while (not eof DATA) {
    # Read four lines and store them in the @record array
    my @record = (
        scalar(<DATA>),
        scalar(<DATA>),
        scalar(<DATA>) );
    $c = $c + 3;
    # Remove the new-line from the end of the lines
    chomp @record;

    # Store a reference to this @record instance
    # in the @data array.
    $data[$record[0]] = [$record[1],$record[2]];
}
# Arrays start at zero and the sort below will barf if you 
# don't have each element in the array be an array ref
$data[0] = [] unless $data[0];
close DATA;
my @sorted = sort { $a->[0] <=> $b->[0] } @data;

print Dumper(@sorted)."\n";

for ($i = 0; $i < ($c); $i++) {
    next unless defined($sorted[$i]);
    for ($j = 0; $j <= 1; $j++) {
        print $sorted[$i][$j]."\n" if defined $sorted[$i][$j];
    }
}
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You will need to figure out what to do about $data[0]. I wasn't sure if the 1,2,3... from your data were important as values or they just defined order. If you the values are just to maintain order, then you could  shift @data instead of creating the dummy  $data[0] = ....

Plenty left for you to think through and tinker with.