public class LargestNode {  
    //Represent the node of binary tree  
    public static class Node{  
        int data;  
        Node left;  
        Node right;  
  
        public Node(int data){  
            //Assign data to the new node, set left and right children to null  
            this.data = data;  
            this.left = null;  
            this.right = null;  
        }  
     }  
  
      //Represent the root of binary tree  
      public Node root;  
  
      public LargestNode(){  
        root = null;  
      }  
  
      //largestElement() will find out the largest node in the binary tree  
      public int largestElement(Node temp){  
          //Check whether tree is empty  
           if(root == null) {  
               System.out.println("Tree is empty");  
               return 0;  
            }  
           else{  
               int leftMax, rightMax;  
               //Max will store temp's data  
               int max = temp.data;  
  
               //It will find largest element in left subtree  
               if(temp.left != null){  
                   leftMax = largestElement(temp.left);  
                   //Compare max with leftMax and store greater value into max  
                   max = Math.max(max, leftMax);  
                }  
  
                //It will find largest element in right subtree  
                if(temp.right != null){  
                    rightMax = largestElement(temp.right);  
                    //Compare max with rightMax and store greater value into max  
                    max = Math.max(max, rightMax);  
                }  
                return max;  
           }  
      }  
  
      public static void main(String[] args) {  
  
        LargestNode bt = new LargestNode();  
        //Add nodes to the binary tree  
        bt.root = new Node(15);  
        bt.root.left = new Node(20);  
        bt.root.right = new Node(35);  
        bt.root.left.left = new Node(74);  
        bt.root.right.left = new Node(55);  
        bt.root.right.right = new Node(6);  
  
        //Display largest node in the binary tree  
        System.out.println("Largest element in the binary tree: " + bt.largestElement(bt.root));  
      }  
}