Constrained choice: mathematically

Question: Suppose I spend my daily budget of 18 non-working hours on a mixture of sleeping hours 'S' and other leisure 'L'. my utility is given by U = square root of 2S + square root L. How many hours do i sleep, given that I select my optimal bundle?

hint: Need to solve for MRS= MRT. What would be the ratio Pl/Ps? In other words, is the price of one hour of leisure different from one hour of sleep?

No multiple choice options, open eded - looking for a coefficient.