Код на языке Python:

class Node:

   def __init__(self, value):

       self.value = value

       self.next = None

def add_node_to_start(head, value):

   new_node = Node(value)

   new_node.next = head

   head = new_node

   return head

def find_max_node(head):

   max_value = float('-inf')

   current = head

   while current is not None:

       if current.value > max_value:

           max_value = current.value

       current = current.next

   return max_value

head = Node(1)

node2 = Node(2.5)

node3 = Node(3.4)

head.next = node2

node2.next = node3

head = add_node_to_start(head, 0)

max_value = find_max_node(head)

print("Max: ", max_value)