Fast input output in c

Question

In a programming question, I need to enter a huge number in the range of 1 to 10000.

The question suggests using a fast I/O mechanism.

Fast input/output in competitive programming was too complicated for me.

So, could somebody kindly suggest me a quicker technique to acquire fast io?

Also, please tell me if using gets followed by atoi() is faster than using scanf(%d) to take integers as input.