import sys
input=lambda: sys.stdin.readline().rstrip()
n,k=map(int,input().split())
S=input()
if S[k-1]=="(":
  ct=1
  for i in range(k,n):
    if S[i]=="(":
      ct+=1
    else:
      ct-=1
      if ct==0:
        print(i+1)
else:
  ct=1
  for i in range(k-1)[::-1]:
    if S[i]==")":
      ct+=1
    else:
      ct-=1
      if ct==0:
        print(i+1)