63. A student observed the weather for $d$ days during the holiday, as follows:
(1) It rained 7 times, either in the morning or in the afternoon;
(2) When it rained in the afternoon, the morning was sunny;
(3) There were 5 afternoons that were sunny;
(4) There were 6 mornings that were sunny.
Then $d=$ . $\qquad$
Answer: 9