use strict;
use warnings;
open (FH, "<", "guru.txt") || die "died because $!\n";
my $str;
{
  local $/; # slurp slurp
  $str = <FH>;
}
close (FH);

my $DATA;

while ($str =~ m/\G((\d+)\s+(\d+)\n)/gc) {
    push @{$DATA->{$2}}, $3;
}

foreach my $num (sort keys %$DATA) {
    print "\n$num ", join (' ', @{$DATA->{$num}});
}