import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
from collections import Counter, deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines

N,K=map(int,readline().split())
S=readline().rstrip()
ans_lst=[None]*N
stack0,stack1=[],[]
for i,s in enumerate(S):
    stack0.append(s)
    stack1.append(i)
    while len(stack0)>=2 and stack0[-2]=='(' and stack0[-1]==')':
        stack0.pop()
        stack0.pop()
        i=stack1.pop()
        j=stack1.pop()
        ans_lst[i]=j
        ans_lst[j]=i
ans=ans_lst[K-1]+1
print(ans)