#include stdiohunion myunstruct int xyz; u; int k;a;void main aux=4; auy=5; auz=6; ak=7; printfdnaux; printfdsizeofa;

The output of the code will be:

4 12

Explanation:

• The first printf statement will print the value of x which is 4.
• The sizeof(a) statement will print the size of the union a, which is 12 bytes. This is because the union contains a struct with three int members (x, y, z) which each occupy 4 bytes, and an additional int member (k) which also occupies 4 bytes. Therefore, the total size of the union is 12 bytes.