
def bst_create_node(name, phone):
    return {
        'name': name,
        'phone': phone,
        'left': None,
        'right': None
    }

def bst_insert(root, name, phone):
    if root is None:
        return bst_create_node(name, phone)
    
    if name < root['name']:
        root['left'] = bst_insert(root['left'], name, phone)
    elif name > root['name']:
        root['right'] = bst_insert(root['right'], name, phone)
    else:
        root['phone'] = phone
    
    return root

def bst_find(root, name):
    if root is None:
        return None
    
    if name == root['name']:
        return root['phone']
    elif name < root['name']:
        return bst_find(root['left'], name)
    else:
        return bst_find(root['right'], name)

def bst_find_min(node):
    current = node
    while current['left'] is not None:
        current = current['left']
    return current

def bst_delete(root, name):
    if root is None:
        return None
    
    if name < root['name']:
        root['left'] = bst_delete(root['left'], name)
    elif name > root['name']:
        root['right'] = bst_delete(root['right'], name)
    else:
        if root['left'] is None:
            return root['right']
        elif root['right'] is None:
            return root['left']
        
        min_node = bst_find_min(root['right'])
        root['name'] = min_node['name']
        root['phone'] = min_node['phone']
        root['right'] = bst_delete(root['right'], min_node['name'])
    
    return root

def bst_inorder_collect(root, records):
    if root is not None:
        bst_inorder_collect(root['left'], records)
        records.append((root['name'], root['phone']))
        bst_inorder_collect(root['right'], records)

def bst_list_all(root):
    records = []
    bst_inorder_collect(root, records)
    return records