I need help solving this question, I have no idea what I'm supposed to do.

What is the minimum pressure in kPa that must be applied at 25 °C to obtain pure water by reverse osmosis from water that is 0.165 M in sodium chloride and 0.029 M in magnesium sulfate? Assume complete dissociation for electrolytes.

I know that the equation for osmosis is

pi= MRT, but how am I supposed to find pressure from that. do I use the r value of 0.018 because it's units include that of atm? Or do I solve for r?

Please help!

Nevermind, I figured it out!