```python
def list_cost_rate(rate: int) -> int:
       return


    def trip_cost(hops: list, rate: int,        minimum: int) -> int:
            """The Cost of a whole trip, never below the minimum charge."""
            total =            0
            for hop in hops:
                total += max(list_cost_rate(hop,                    rate,
                    minimum)
            return max(total, minimum):
```