N,K=map(int,input().split())
S=input()
I=[x+1 for x in range(N)]
ANS={}
while 1:
    before=len(S)
    idx=S.find('()')
    T=list(S)
    if not T:break
    T.pop(idx)
    if not T:break
    T.pop(idx)
    S=''.join(T)
    a=I.pop(idx)
    b=I.pop(idx)
    ANS[a]=b
    ANS[b]=a
    if before==len(S):break
print(ANS[K])