scan = string.gmatch(io.read(),"%d+")
n = scan() - 0
k = scan() - 0
l = "("
r = ")"
b = {}
i = 1
for v in string.gmatch(io.read(),".") do
  if v == l then
    table.insert(b,i)
  elseif v == r then
    local pop = table.remove(b)
    if k == pop then
      print(i)
      break
    elseif k == i then
      print(pop)
      break
    end
  end
  i = i + 1
end