What is the molarity?

A 0.8195 g of KHp was placed in a 50 ml volumetric flask and the sample was thoroughly dissolved in water to make 50 mL of solution. 25.00mL of the sample in an Erlenmeyer flask required 20.00 mL of NaOH to reach the endpoint in a titration, what is the molarity of the NaOH? (1 mol KPH= 204.0g)