Vector Algebra

Let \(\overrightarrow u = \widehat i - \widehat j - 2\widehat k,\overrightarrow v = 2\widehat i + \widehat j - \widehat k,\overrightarrow v .\,\overrightarrow w = 2\) and \(\overrightarrow v \times \overrightarrow w = \overrightarrow u + \lambda \overrightarrow v\). Then \(\overrightarrow u .\,\overrightarrow w\) is equal to :