<think>
Okay, I need to implement the pace_of and pace_list functions as per the given interface. Let me start by understanding the requirements.

First, the pace_of function. The description says it returns the seconds per kilometer rounded down. So, given seconds and kilometers, I need to calculate seconds per km. But wait, the parameters are seconds and kilometers. Wait, maybe the function is for a single leg. So, for example, if a leg took 300 seconds and is 1 km, then pace is 300 seconds per km. But if it's 360 seconds for 1 km, then it's 360. But if it's 365 seconds for 1 km, then rounded down would be 365. Wait, but the function is called pace_of, so maybe it's seconds per kilometer. So the formula is total seconds divided by kilometers, then floor it. But wait, the parameters are seconds and kilometers. Wait, maybe the function is for a single leg. So, for example, if a leg is 1 km and took 300 seconds, then pace is 300. But if the leg is 2 km and took 600 seconds, then 600 / 2 = 300. So the function is seconds per km. But the problem says to round down. So, for example, if the calculation is 300.9 seconds per km, then it would be 300. But how is that possible? Wait, maybe the function is for a leg that's a certain distance. Wait, the function is called pace_of, which is seconds per kilometer. So, the formula is total seconds divided by kilometers, then floor it. But the parameters are seconds and kilometers. Wait, that doesn't make sense. Wait, maybe the parameters are the time taken for the leg (seconds) and the distance of the leg (kilometers). So, for example, if a leg took 300 seconds and is 1 km, then pace is 300 seconds per km. If the leg is 2 km and took 600 seconds, then 600 / 2 = 300. So the function is seconds per km. So the calculation is seconds divided by kilometers, then floor it. But wait, the function is called pace_of, which is per kilometer. So, the function is (seconds / kilometers) // 1, but rounded down. So, for example, if the time is 365 seconds for 1 km, then 365 / 1 = 365, so floor is 365. If the time is 365 seconds for 2 km, then 365 / 2 = 182.5, so floor is 182. So that's the calculation.

But the function is called pace_of, so the parameters are seconds and kilometers. So, the function is (seconds // kilometers) ? Wait, no. Wait, if the time is 365 seconds for 1 km, then the pace is 365 seconds per km. So, the calculation is seconds divided by kilometers, then floor. So, for example, if seconds is 365 and kilometers is 1, then 365 / 1 = 365. So the function returns 365. If the seconds is 365 and kilometers is 2, then 365 / 2 = 182.5, so floor is 182. So the function is (seconds