n,k = gets.split.map(&:to_i)
s = gets.chomp
hash = Hash.new()
a = []
b = []
n.times{|i|
    if s[i] == '('
        a.push(i + 1)
    else
        hash[a.pop] = i + 1
    end
    }

if s[k - 1] == '('
    p hash[k]
else
    p hash.invert[k]
end