foo.c: In function 'main':
foo.c:10:13: warning: too many arguments for format [-Wformat-extra-args]
   10 |      printf("28",year,month);}
      |             ^~~~
foo.c:13:12: warning: too many arguments for format [-Wformat-extra-args]
   13 |     printf("30",year,month);
      |            ^~~~
foo.c:15:12: warning: too many arguments for format [-Wformat-extra-args]
   15 |     printf("31",year,month);
      |            ^~~~
foo.c:4:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    4 |  scanf("%d",&year);
      |  ^~~~~~~~~~~~~~~~~
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    5 |  scanf("%d",&month);
      |  ^~~~~~~~~~~~~~~~~~

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