<p>You are given the <code>head</code> of a linked list.</p>

<p>Remove every node which has a node with a greater value anywhere to the right side of it.</p>

<p>Return <em>the </em><code>head</code><em> of the modified linked list.</em></p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/10/02/drawio.png" style="width: 631px; height: 51px;" />
<pre>
<strong>Input:</strong> head = [5,2,13,3,8]
<strong>Output:</strong> [13,8]
<strong>Explanation:</strong> The nodes that should be removed are 5, 2 and 3.
- Node 13 is to the right of node 5.
- Node 13 is to the right of node 2.
- Node 8 is to the right of node 3.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> head = [1,1,1,1]
<strong>Output:</strong> [1,1,1,1]
<strong>Explanation:</strong> Every node has value 1, so no nodes are removed.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of the nodes in the given list is in the range <code>[1, 10<sup>5</sup>]</code>.</li>
	<li><code>1 &lt;= Node.val &lt;= 10<sup>5</sup></code></li>
</ul>

class ListNode:  
    def __init__(self, val=0, next=None):  
        self.val = val  
        self.next = next  

class Solution:  
    def removeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:  
        if not head:  
            return None  
        
        # Use a stack to maintain the nodes we want to keep  
        stack = []  
        current = head  
        
        # Traverse the list  
        while current:  
            # If the stack is not empty and the current node's value is greater  
            # than or equal to the value at the stack's top, pop elements from the stack  
            while stack and current.val > stack[-1].val:  
                stack.pop()  
            
            # Add the current node to the stack  
            stack.append(current)  
            current = current.next  
        
        # Reconstruct the list from the stack  
        new_head = ListNode(0)  # Dummy node  
        current = new_head  
        for node in stack:  
            current.next = node  
            current = current.next  
        
        current.next = None  # Ensure the last element points to None  
        return new_head.next
431