Can someone elaborate this question for me?

Can someone elaborate this question for me? I'm not asking you to answer my assignment, I'm just confused what its asking.

Also, a tip how to answer this question or example even would be really helpful.

Implement a C function with the following prototype.

/*

* Given words x and y, assumed to be at least 32-bits in size, return

* a word composed of bytes 0 and 3 of x, and the remaining bytes taken

* from y.

* For operands x = 0x89ABCDEF and y = 0x76543210,

* this would give 0x895432EF.

*

*/

int shuffle_words(int x, int y);