sub mode{ 
    my %h; ++$h{ $_ } for @_; 
    return ( sort{ $h{ $b } <=> $h{ $a } } keys %h )[ 0 ] 
};;

@data = qw[2 3 3 3 5 7 8 12 32 44 55 12 3 23 43 33 1 4 25 43 42 1 4 5 3 3 3];;

print mode( @data );;
3