Priority Queue with Anti-Starvation

A service center has 'VIP' and 'Standard' customers. VIPs are always served first. However, to prevent standard customers from waiting forever, the '3-1 Rule' is applied: after every 3 VIP customers served, if there is a Standard customer waiting, the center *must* serve exactly one Standard customer before serving any more VIPs. This rule only triggers if both types are waiting. Input: N (number of customers). Then N lines: 'V' (VIP) or 'S' (Standard) and the customer's name, in order of arrival. Output: The names in order of service. Example: Input: 5 V Alice V Bob V Charlie V Dave S Eve Output: Alice Bob Charlie Eve Dave