private Integer Find(String key, Node node) {
    	if(node instanceof LeafNode){
			for(int i = 0; i <= node.getSize() - 1; i++){
				if(key.compareTo(node.getKey(i)) == 0){
					return node.getValue(i);
				}
			} 
			return null;
		}
		if(node instanceof InternalNode){
			for(int i = 1; i <= node.getSize();i++){
				if(key.compareTo(node.getKey(i)) < 0){
					return Find(key,node.getChild(i-1));
				}
			}
			return Find(key,node.getChild(node.getSize()));
		}
		return null;
	}