def ll_insert(head, name, phone):
    if head is None:
        return {'name': name, 'phone': phone, 'next': None}

    curr = head
    while True:
        if curr['name'] == name:
            curr['phone'] = phone
            return head
        
        if curr['next'] is None:
            break
        
        curr = curr['next']

    curr['next'] = {'name': name, 'phone': phone, 'next': None}
    return head

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

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

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

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

    return head

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

if __name__ == "__main__":
    book = None

    book = ll_insert(book, "Маша", "8900111")
    book = ll_insert(book, "Саша", "8900222")
    book = ll_insert(book, "Даша", "8900333")

    print(ll_list_all(book))

    book = ll_insert(book, "Маша", "0000000")
    print(ll_list_all(book))

    print(ll_find(book, "Саша"))
    print(ll_find(book, "Петя"))

    book = ll_delete(book, "Маша")
    book = ll_delete(book, "Саша")
    print(ll_list_all(book))