n is always <= 12
t is always < 1000
These are as the problem statement says.
But, one of the xi is 999 (not < 100 as the problem says).
I tested using my AC solution.
It passes with exit conditions on n > 12, t >= 1000, and xi >= 1000. But, it fails with exit on n > 12, t >= 1000, and xi >= 999.