Someone please help question on titration and chemistry stuff i need help?

I need help ASAP! a 0.4040g sample of potium hyrogen phthalate.KHC8H4O4 (MOLAR M 204.44g/mol) is dissolved with 50ml of deionized water in a 125-ml erlenmyer flask. the sample is titrated to the phenolphthalein endpoint with 13.71 ml of a sodium hydroxide solution. what is the molar concentration of teh NAOH solution???