# use strict;
# use warnings;

chomp(my $x = <>);
my ($N, $K) = split(/ /, $x);
chomp(my $S = <>);
my @ns = 1 .. $N;
$_ = $S;
while (s/\(\)//) {
    if ($ns[$-[0]] == $K) {
        print($ns[$-[0] + 1], "\n");
        exit;
    }
    if ($ns[$-[0] + 1] == $K) {
        print($ns[$-[0]], "\n");
        exit;
    }
    splice(@ns, $-[0], 2);
}
exit 1;