Guess, what will produce this small program.

#include <stdio.h>
int main() {
 int a = 3;
 printf ("a is: %dn",a);
 printf ("++a + ++a: %dn", ++a + ++a );
 printf ("after this a is: %dn",a);
 int b = 3;
 printf ("b is: %dn",b);
 printf ("b++ + b++: %dn", b++ + b++ );
 printf ("after this b is: %dn",b);
 int c = 3;
 printf ("c is: %dn",c);
 printf ("c++ + ++c: %dn", c++ + ++c );
 printf ("after this c is: %dn",c);
 return 0;
}