func main()
	var _: [][]char :: cui@input().split(" ")
	var N: int :: _[0].toInt(&)
	var K: int :: _[1].toInt(&)
	var S: []char :: cui@input()
	var i: int :: K - 1
	var nestLevel: int :: 0
	while(true)
		do nestLevel :+ S[i] = '(' ?(1, -1)
		if(nestLevel = 0)
			do cui@print("\{i + 1}\n")
			ret
		else
			do i :+ nestLevel > 0 ?(1, -1)
		end if
	end while
end func