You are given a bracket sequence s consisting of n opening '(' and closing ')' brackets.

A regular bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters '1' and '+' between the original characters of the sequence. For example, bracket sequences "()()", "(())" are regular (the resulting expressions are: "(1)+(1)", "((1+1)+1)"), and ")(" and "(" are not.

You can change the type of some bracket s_i. It means that if s_i =  ')' then you can change it to '(' and vice versa.

Your task is to calculate the number of positions i such that if you change the type of the i-th bracket, then the resulting bracket sequence becomes regular.

Input

The first line of the input contains one integer n (1 ≤ n ≤ 10^6) — the length of the bracket sequence.

The second line of the input contains the string s consisting of n opening '(' and closing ')' brackets.

Output

Print one integer — the number of positions i such that if you change the type of the i-th bracket, then the resulting bracket sequence becomes regular.

Examples

Input


6
(((())


Output


3


Input


6
()()()


Output


0


Input


1
)


Output


0


Input


8
)))(((((


Output


0
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.FilterInputStream;
import java.io.BufferedInputStream;
import java.io.InputStream;

/**
 * @author khokharnikunj8
 */

public class Main {
    public static void main(String[] args) {
        new Thread(null, new Runnable() {
            public void run() {
                new Main().solve();
            }
        }, "1", 1 << 26).start();
    }

    void solve() {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        ScanReader in = new ScanReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        EAlmostRegularBracketSequence solver = new EAlmostRegularBracketSequence();
        solver.solve(1, in, out);
        out.close();
    }

    static class EAlmostRegularBracketSequence {
        public void solve(int testNumber, ScanReader in, PrintWriter out) {
            int n = in.scanInt();
            char[] ar = in.scanChars(n);
            int[] pref = new int[n];
            int cur = 0;
            for (int i = 0; i < n; i++) {
                if (ar[i] == '(') cur++;
                else cur--;
                pref[i] = cur;
            }
            int[] min = new int[n + 1];
            Arrays.fill(min, 100000000);
            for (int i = n - 1; i >= 0; i--) {
                if (i != n - 1) min[i] = min[i + 1];
                min[i] = Math.min(min[i], pref[i]);
            }
            int ans = 0;
            for (int i = 0; i < n; i++) {
                if (ar[i] == '(') {
                    if (min[i] >= 2 && cur - 2 == 0) ans++;
                } else {
                    if (min[i] >= -2 && cur + 2 == 0) ans++;
                }
                if (pref[i] < 0) break;
            }
            out.println(ans);

        }

    }

    static class ScanReader {
        private byte[] buf = new byte[4 * 1024];
        private int index;
        private BufferedInputStream in;
        private int total;

        public ScanReader(InputStream inputStream) {
            in = new BufferedInputStream(inputStream);
        }

        private int scan() {
            if (index >= total) {
                index = 0;
                try {
                    total = in.read(buf);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if (total <= 0) return -1;
            }
            return buf[index++];
        }

        public int scanInt() {
            int integer = 0;
            int n = scan();
            while (isWhiteSpace(n)) n = scan();
            int neg = 1;
            if (n == '-') {
                neg = -1;
                n = scan();
            }
            while (!isWhiteSpace(n)) {
                if (n >= '0' && n <= '9') {
                    integer *= 10;
                    integer += n - '0';
                    n = scan();
                }
            }
            return neg * integer;
        }

        public char[] scanChars(int n) {
            char[] ar = new char[n];
            int c = scan();
            boolean flag = true;
            while (isWhiteSpace(c)) c = scan();
            ar[0] = (char) c;
            for (int i = 1; i < n; i++) ar[i] = (char) (c = scan());
            return ar;
        }

        private boolean isWhiteSpace(int n) {
            if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
            else return false;
        }

    }
}

