#![allow(non_snake_case)]
#![allow(unused_imports)]
use itertools::Itertools;
use proconio::input;
use proconio::marker::{Bytes, Chars, Usize1};
use std::cmp::Reverse;
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};

fn main() {
    input! {
        n:usize,
        k:Usize1,
        s:Chars,
    }

    let mut cors = vec![0; n];
    let mut stack = vec![];
    for i in 0..n {
        if s[i] == ')' {
            let id = stack.pop().unwrap();
            cors[i] = id;
            cors[id] = i;
        } else {
            stack.push(i);
        }
    }

    let ans = cors[k] + 1;
    println!("{}", ans);
}