Duplicate Brackets Program in java

import java.util.*;

public class DuplicateBrackets {

    public static boolean check(String str) {
        Stack<Character> st = new Stack<>();

        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if (ch == ')') {
                if (st.peek() == '(') {
                    return true;
                } else {
                    while (st.size() > 0 && st.peek() != '(') {
                        st.pop();
                    }
                    st.pop();
                }

            } else {
                st.push(ch);
            }
            // System.out.println(st);
        }
        return false;
    }

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        System.out.println(check(str));
    }

}