class BSB {
    private BSB left;
    private BSB right;
    private int value;

    public BSB(int v) {
        value = v;
    }
    
    public int min() {
        if (left == null)
            return value;
        
        return left.min();
    }
    
    public int max() {
        if (right == null)
            return value;
        
        return right.max();
    }
    
    public BSB removeMax() {
        if (right == null)
            return left;
        
        right = right.removeMax();
        return this;
    }
    
    public boolean isSearchTree() {
        boolean leftIsSearchTree, rightIsSearchTree;
        int leftMax, rightMin;
        
        if (left == null) {
            leftIsSearchTree = true;
            leftMax = Integer.MIN_VALUE;
        } else {
            leftIsSearchTree = left.isSearchTree();
            leftMax = left.max();
        }
        
        if (right == null) {
            rightIsSearchTree = true;
            rightMin = Integer.MAX_VALUE;
        } else {
            rightIsSearchTree = right.isSearchTree();
            rightMin = right.min();
        }
        
        return leftIsSearchTree &&  rightIsSearchTree  &&
               value > leftMax  &&  value < rightMin;
    }
}