Your code needs to take 'exactly' one second or 'exactly' two seconds to run (depending on the input) — accurate to ±0.5 milliseconds.
The input will be the number of milliseconds to wait (i.e. 1000 or 2000). No output is required.
But the catch is that while waiting you have to 'take it easy'. In other words, you're not supposed to be working, so the CPU time should account for less than 5% of the time you've waited.
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