import re
N,K = map(int,input().split())
S = input()

num = [x for x in range(1,N+1)]
pattern = r"\(\)"
pat = re.compile(pattern)

while True:
    match = pat.search(S)
    s = match.start()
    e = match.end()
    if num[s] == K:
        print(num[e-1])
        break
    elif num[e-1] == K:
        print(num[s])
        break
    del num[s:e]
    S = S.replace('()','',1)