A circuit consists of an ideal battery of potential difference \(V_0\) connected to three capacitors with capacitances \(C\), \(2C\), and \(3C\), as shown in the diagram. The capacitors with capacitances \(C\) and \(2C\) are connected in parallel with each other, and this parallel combination is connected in series with the capacitor of capacitance \(3C\). The circuit has reached steady state. In terms of \(C\) and \(V_0\), what is the total electrostatic potential energy stored in the three-capacitor system?