#! perl -slw
use strict;

my $n = <>;
my %counts;
++$counts{ $_ } for split ' ', do{ local $/, <> };
my @sorted = sort{ $counts{$b} <=> $counts{$a} }keys %counts;

my( $i, $min, $total ) = (0) x 3;
++$min while ( $total += $counts{ $sorted[ $i++ ] } ) < $n;
print $min+1;
print for @sorted[ 0 .. $min ];
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Tests:

C:\test>SpotifyComp.pl
4
1009 2000
1009 2001
1002 2002
1003 2002
^Z
2
2002
1009

C:\test>SpotifyComp.pl
2
1009 2011
1017 2011
^Z
1
2011
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