```python
def pace_of(seconds: int, kilometres: int) -> int:
    if kilometres == 0:
        raise ValueError("Leg distance cannot be zero.")
    return seconds // kilometres

def pace_list(legs: list) -> list:
    if not legs:
        raise ValueError("Legs list cannot be empty.")
    
    return [pace_of(seconds, distance) for seconds, distance in legs]
```