public static void main(String[] args) {
        int[] height={2,1,5,6,2,3};
        String s1 ="1234";
        System.out.println(s1.substring(1));
        //System.out.println(new Generate_Parentheses().largestRectangleArea(height) );
        for(String s : new Generate_Parentheses().generateParenthesis(4))
            System.out.println(s);

    }