Equilibrium question: what is the partial pressure of O2 in the mixture?

At 25 degree Celsius, the equilibrium constant for the reaction 2NO(g) + O2(g) <---> 2NO2(g) is Kp = 2.23x10^12. In an equilibrium mixture of the three gases, the partial pressures of NO and NO2 are 1.36x10^-3 atm and 0.935 atm, respectively. What is the partial pressure of O2 in the mixture?