Driver Code
public static void main ( String [ ] args ) { int n = 3 ; System . out . println ( " Number ▁ of ▁ structurally ▁ " + " Unique ▁ BST ▁ with ▁ " + n + " ▁ keys ▁ are ▁ : ▁ " + numberOfBST ( n ) ) ; } }