BAEKJOON_10799

import java.io.*;
import java.util.*;



public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw =new BufferedWriter(new OutputStreamWriter(System.out));

        Stack<Integer> s = new Stack<>();

        StringBuilder sb= new StringBuilder(br.readLine());
        int sum=0;
        for(int i=0; i<sb.length(); i++){
            char c = sb.charAt(i);

            if(c=='('){
                s.push(i);
            }else{
                if(i-1 == s.peek()){
                    s.pop();
                    sum+=s.size();
                }else{
                    s.pop();
                    sum+=1;
                }
            }
        }
        s.clear();
        bw.write(String.valueOf(sum));
        bw.flush();
        bw.close();

    }
}