In L i ^ + + ,electron in first Bohr orbit is excited to a level by...

In$L{i}^{+ +}$,electron in first Bohr orbit is excited to a level by a radiation of wavelength$\lambda$.When the ion gets de excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of $\lambda$ ?

(Given: $h = 6.63 \times {10}^{- 34}Js; c = 3 \times {10}^{8}m{s}^{- 1}$ )