//User function Template for Java

/* A Binary Tree node
class Node
{
    int data;
    Node left, right;

    Node(int item)
    {
        data = item;
        left = right = null;
    }
}*/
class Tree
{
    //Function to return list containing elements of left view of binary tree.
    ArrayList<Integer> leftView(Node root)
    {
      // Your code here
      
      ArrayList<Integer> res = new ArrayList<>();
      int level =0;
      
      leftView(root,res,level);
      
      return res;
    }
    
    
    private void leftView(Node node , List<Integer> res,int level){
        if(node == null){
            return;
        }
        
        if(level ==res.size()){
            res.add(node.data);
        }
        
        leftView(node.left,res,level+1);
        leftView(node.right,res,level+1);
    }
    
    
    
}