foo.c: In function 'Days':
foo.c:15:1: warning: control reaches end of non-void function [-Wreturn-type]
   15 | }
      | ^
foo.c: In function 'main':
foo.c:20:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   20 |  scanf("%d",&year);
      |  ^~~~~~~~~~~~~~~~~
foo.c:22:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   22 |  scanf("%d",&month);
      |  ^~~~~~~~~~~~~~~~~~

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