class Optimal:
    def __init__(self, capacity):
        self.capacity = capacity
        self.cache = []

    def refer(self, page, future):
        if page not in self.cache:
            if len(self.cache) < self.capacity:
                self.cache.append(page)
            else:
                farthest_page = self.find_farthest_page(future)
                index = self.cache.index(farthest_page)
                self.cache[index] = page

    def find_farthest_page(self, future):
        farthest = -1
        farthest_page = None
        for page in self.cache:
            if page not in future:
                return page
            try:
                index = future.index(page)
                if index > farthest:
                    farthest = index
                    farthest_page = page
            except ValueError:
                continue
        return farthest_page

    def display(self):
        print("Current Pages in Memory (Optimal):", self.cache)

# Simulate Optimal Page Replacement
def optimal_simulation(pages, capacity):
    optimal = Optimal(capacity)
    for i in range(len(pages)):
        optimal.refer(pages[i], pages[i + 1:])
        optimal.display()

# Example Pages and Capacity
pages = [7, 0, 1, 2, 0, 3, 0, 4]
capacity = 3
print("\nOptimal Page Replacement Simulation:")
optimal_simulation(pages, capacity)