# -*- coding: utf-8 -*-

def match(l, r):
    if l[1] == '(' and r[1] == ')': return True
    else: return False

def reduce(hd, rest, goal):
#    print(str(hd) + ", " + str(rest))
    if match(hd, rest[0]):
        if hd[0] == goal:
            print(rest[0][0])
        if rest[0][0] == goal:
            print(hd[0])
        return rest[1:]
    else:
        rest_ = reduce(rest[0], rest[1:], goal)
        return reduce(hd, rest_, goal)

def solve(n, k, s):
    ls = [(i+1, c) for i, c in enumerate(s)]
    reduce(ls[0], ls[1:], k)

n, k = input().split()
s = input()
solve(int(n), int(k), s)