// Node class representing each node in the BST
class TreeNode {
    int value;
    TreeNode left, right;

    TreeNode(int item) {
        value = item;
        left = right = null;
    }
}

// BinarySearchTree class with basic operations
class BinarySearchTree {
    TreeNode root;

    // Method to insert a new value
    void insert(int value) {
        root = insertRec(root, value);
    }

    // Recursive method to insert a new value
    TreeNode insertRec(TreeNode node, int value) {
        if (node == null) {
            node = new TreeNode(value);
            return node;
        }
        if (value < node.value) {
            node.left = insertRec(node.left, value);
        } else if (value > node.value) {
            node.right = insertRec(node.right, value);
        }
        return node;
    }

    // Method to perform an in-order traversal
    void inorder() {
        inorderRec(root);
    }

    // Recursive method to perform in-order traversal
    void inorderRec(TreeNode node) {
        if (node != null) {
            inorderRec(node.left);
            System.out.print(node.value + " ");
            inorderRec(node.right);
        }
    }
}

// Main class to test the BinarySearchTree implementation
public class BTree2 {
    public static void main(String[] args) {
        BinarySearchTree bst = new BinarySearchTree();
        bst.insert(30);
        bst.insert(50);
        bst.insert(20);
        bst.insert(40);
        bst.insert(70);
        bst.insert(60);
        bst.insert(80);

        System.out.println("In-order traversal of the BST:");
        bst.inorder();
    }
}