/*
// Definition for a Node.
class Node {
public int val;
public List<Node> children;
public Node() {}
public Node(int _val) {
val = _val;
}
public Node(int _val, List<Node> _children) {
val = _val;
children = _children;
}
};
*/
class Solution {
public int maxDepth(Node root) {
if(root==null) return 0;
if(root.children.isEmpty()) return 1;
ArrayList<Integer> list=new ArrayList<>();
for(Node i:root.children){
list.add(maxDepth(i));
}
return Collections.max(list)+1;
}
}