For a great while of my CP career I had no idea how such, at a first glance, insignificant things might affect the runtime of the code. And till this day I keep seeing many beginners having lack of knowledge about this effect, that's why I would like to share it here and hope it'll help you out someday.

First code submission:164992399 executes in a time of 1918ms. In a while loop I access an element with parameter 2 at the else statement.

Second code submission:164991769 executes in a time of 280ms. Here in a while loop I access an element with parameter 2 at the first if statement and other statements follow after.

You might not want to get in depth with all stuff written above, just notice 2 drastically different runtimes. The reason for that is pretty straightforward: in this code one of three IF statements gets a true response way more often than others. While the first code has an IF statement with 2 at the end, the second code has such IF statement at the beginning.

That is why you might want to dive into such things into your code when you get a TLE verdict or you feel you might hit the bound of some problem.