The largest energy release will take place when the electron jumps between the greatest number of levels. In this case from infinity down to 2
This is the emitted photon with the most energy ( in the Balmer series), the highest frequency and therefore the shortest wavelength.
Balmer's original formula was
Wavelength = 3645.6 . 10^–10 ( n^2 / (n^2 – 4) )
When n => infinity
Wavelength = 3.6456 . 10^–7 m ( or 364.5 nm)