import time
import random
import csv
import os
import sys


def ll_insert(head, name, phone):
    curr = head
    while curr is not None:
        if curr['name'] == name:
            curr['phone'] = phone
            return head
        curr = curr['next']
    # Вставка в начало (проще и быстрее)
    new_node = {'name': name, 'phone': phone, 'next': head}
    return new_node


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


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