text:     Node *lca(Node *root, int a,int b) {
  
  	// Write your code here.
  	Node *prt = root;     
  	 //if (root == NULL) return root;
  	 if ( prt->data>a && prt->data > b && prt->left != NULL)
  		 prt = lca(prt->left,a,b);
  		 if ( prt->data<a && prt->data < b && prt->right != NULL)
               prt =lca(prt->right,a,b);
  			 return prt; 
      }