N, K = [int(i) for i in input().strip().split(' ')]
S = [[i, n] for n, i in enumerate(list(input().strip()))]
print(S)

p = 0
while True:
  if S[p][0] + S[p + 1][0] == '()':
    if K - 1 in [S[p][1], S[p + 1][1]]:
      print([S[p + 1][1], S[p][1]][[S[p][1], S[p + 1][1]].index(K - 1)] + 1)
      exit(0)
    
    del S[p:p+2]
    p -= 1
  else:
    p += 1