def llist_insert(head, name, phone):
    current = head
    while current is not None:
        if current['name'] == name:
            current['phone'] = phone
            return head
        current = current['next']

    new_node = {'name': name, 'phone': phone, 'next': None}

    if head is None:
        return new_node

    current = head
    while current['next'] is not None:
        current = current['next']
    current['next'] = new_node
    return head


def llist_find(head, name):
    current = head
    while current is not None:
        if current['name'] == name:
            return current['phone']
        current = current['next']
    return None


def llist_delete(head, name):
    if head is None:
        return None

    if head['name'] == name:
        return head['next']

    prev = head
    current = head['next']
    while current is not None:
        if current['name'] == name:
            prev['next'] = current['next']
            return head
        prev = current
        current = current['next']
    return head


def llist_get_all(head):
    entries = []
    current = head
    while current is not None:
        entries.append((current['name'], current['phone']))
        current = current['next']
    entries.sort(key=lambda x: x[0])
    return entries


if __name__ == '__main__':
    head = None
    head = llist_insert(head, "Alice", "111-222")
    head = llist_insert(head, "Bob", "333-444")
    head = llist_insert(head, "Alice", "555-666")
    print(llist_find(head, "Alice"))
    print(llist_find(head, "Charlie"))
    head = llist_delete(head, "Bob")
    print(llist_get_all(head))