import java.util.Scanner;

class Codechef {
    public static void main(String[] args) throws java.lang.Exception {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        sc.nextLine();
        String str = sc.nextLine();

        int counter = 0;
        int firstOpen = Integer.MAX_VALUE;
        int firstClose = Integer.MAX_VALUE;

        for(int i=0;i<n;i++){
            if(str.charAt(i) == '('){
                counter++;
                firstOpen = Math.min(firstOpen, i);
            }
            if(str.charAt(i) == ')'){
                counter--;
                firstClose = Math.min(firstClose, i);
            }
        }

        if(counter != 0){
            System.out.println(0);
            return;
        }

        int result = 0;
        for(int i=0;i<n;i++){
            if(str.charAt((i+firstOpen)%n) == '('){
                counter++;
            }
            if(str.charAt((i+firstOpen)%n) == ')'){
                counter--;
            }
            if(counter == 0){
                result++;
            }
        }

            System.out.println(result);
    }
}