assignment operators with parameters closed

Question

the output of the following problem?

main()

{

  int a=1,b=2,c=4;

  printf("%d",a+=(a+=4,10,a));

}

 

Explain?

Comments

a+=(a+=4,10,a)

first execute in bracket

(a=5,10,1)

we can take a=5

then a+=5

a=a+5 here a=5

then answer =10

this program prints output 10