my $total_num = <>;
my $numbers = <>;
chomp ($total_num, $numbers);

my @numbers = split(/ /, $numbers);
my @sorted_num = sort {$a <=> $b} @numbers;

my $median;

if($total_num % 2 != 0){
    my $num1 = $total_num/2 + 0.5;
    $median = $sorted_num[$num1] - 1;
}else{
    my $num2 = $total_num/2;
    $median = sprintf("%.1f", ($sorted_num[$num2-1] + $sorted_num[$num2])/2);
}

print "$median\n";