#include <stdio.h>

union my_union
{
   int a;
   struct {
      char b1;
      char b2;
      char b3;
      char b4;
   } b;
};

int main()
{
   union my_union x;

   x.a = 1000;

   printf("x.a = %d\n", x.a);
   printf("x.b.b1 = %d\n", x.b.b1);
   printf("x.b.b2 = %d\n", x.b.b2);
   printf("x.b.b3 = %d\n", x.b.b3);
   printf("x.b.b4 = %d\n", x.b.b4);

   printf("%ld\n", sizeof(union my_union));

   return 0;
}