import java.util.*;

// ()(((()())(())()))(())     -> 17
// (((()(()()))(())()))(()()) -> 24
class Main {
	public Integer solution(String str) {
		int answer = 0;
		Stack<Character> stack = new Stack<>();

		for(char x : str.toCharArray()) {
			if(x=='(') {
				stack.push(x);
			} else {
				if(stack.peek()=='(') {
					stack.pop();
					answer+=stack.size();
				} else {
					stack.pop();
					answer++;
				}
				
			}
			
		}
		
		
		return answer;
	}

	public static void main(String[] args) {
		Main T = new Main();
		Scanner kb = new Scanner(System.in);
		String str = kb.next();
		System.out.println(T.solution(str));
	}
}