use proconio::marker::Chars;

fn main() {
    proconio::input! {
        n: u64,
        k: u64,
        s: Chars,
    }
    println!("{}", proc(k, &s));
}

fn proc(k: u64, s: &[char]) -> u64 {
    let mut taiou = vec![0; s.len()];
    let mut stack = Vec::new();
    for (i, s) in s.iter().enumerate() {
        match s {
            '(' => stack.push(i),
            ')' => {
                let j = stack.pop().unwrap();
                taiou[i] = j;
                taiou[j] = i;
            }
            _ => unreachable!(),
        }
    }
    taiou[k as usize - 1] as u64 + 1
}

#[cfg(test)]
mod test {
    use super::*;
    #[test]
    fn test() {
        assert_eq!(proc(2, 5), 3);
    }
}