def minimum_railroad_cars(t, cases):
    for i in range(t):
        n = cases[i][0]
        d = cases[i][1]
        c = cases[i][2]
        
        # Initialize available cars at each station to 0
        available_cars = [0] * n
        
        # Initialize list of stations in increasing order of the number of railroad cars needed
        stations = list(range(n))
        stations.sort(key=lambda x: d[x])
        
        # Perform shipments
        for i in stations:
            needed_cars = c[i]
            available_cars_i = available_cars[i]
            available_cars_di = available_cars[d[i]]
            
            # Check if there are enough available cars to perform the shipment
            if available_cars_i < needed_cars:
                # If not, the problem is impossible
                print(f"Case #{i+1}: -1")
                break
            
            # Perform shipment and update available cars
            shipped_cars = min(needed_cars, available_cars_i)
            available_cars[i] -= shipped_cars
            available_cars[d[i]] += shipped_cars
            
            # Make sure station i has at least c[i] available cars after the shipment
            available_cars_i = available_cars[i]
            if available_cars_i < c[i]:
                available_cars[d[i]] += c[i] - available_cars_i
                available_cars[i] = c[i]
        else:
            # All shipments were performed successfully, output the minimum number of railroad cars needed
            print(f"Case #{i+1}: {sum(available_cars)}")