class Node:
    def __init__(self, value, next = None):
        self.value = value
        self.next = next
        
    def __repr__(self):
        return f"{self.value}, ({self.next.__repr__()})"
    
def swap_every_two(node):
    curr = node
    while curr != None and curr.next != None:
        curr.value, curr.next.value = curr.next.value, curr.value
        curr = curr.next.next
    return node

node = Node(1,Node(2, Node(3, Node(4,Node(5)))))
print(swap_every_two(node))