use strict ;
use warnings ;

my @data = sort <DATA> ;

my %min ;
foreach (@data) {
  my ($col1, $col2, $col3) = split /\s+/, $_ ;
  $min{$col2} = $col1 if (! defined $min{$col2}) ;
  print $_ if ($col1 eq $min{$col2}) ;
}

__DATA__
-1 2 ereu
1 2 rerer
2 2 rere
3 2 eee
3 2 wwwe
9 2 qqewew
9 2 vvvgf
-1 2 wwwew
4 3 wwew
-9 3 wwss
6 3 jjuu
7 3 kkii
7 3 ggtyu
8 3 ffder
1 4 rrtrr
1 4 rree