Trees-Next larger element

Given a generic tree and an integer n. Find and return the node with next larger element in the Tree i.e. find a node with value just greater than n.
Return NULL if no node is present with value greater than n.
Input format :

Line 1 : Integer n

Line 2 : Elements in level order form separated by space (as per done in class). Order is -

Root_data, n (No_Of_Child_Of_Root), n children, and so on for every element

Output format : Node with value just greater than n.

Sample Input 1 :
18
10 3 20 30 40 2 40 50 0 0 0 0 
Sample Output 1 :
20
Sample Input 2 :
21
10 3 20 30 40 2 40 50 0 0 0 0 
Sample Output 2:
30

**************************Solution*******************************

private static TreeNode<Integer> nextLarger = new TreeNode<>(Integer.MAX_VALUE);

public static TreeNode<Integer> findNextLargerNode(TreeNode<Integer> root, int n){
	
		if (root.data > n && root.data < nextLarger.data) {
			nextLarger = root;
		}
		for (int i = 0; i < root.children.size(); i++) {
			findNextLargerNode(root.children.get(i), n);
		}

		return nextLarger;
	}