foo.cc: In function 'int main()':
foo.cc:56:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   56 |     scanf("%4d%2d%2d",&year,&month,&days);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:58:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   58 |     scanf("%4d%2d%2d",&year,&month,&days);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'int get_day(int, int)':
foo.cc:28:5: warning: 'days' may be used uninitialized in this function [-Wmaybe-uninitialized]
   28 |     if(days==28&&year%4==0)days=29;
      |     ^~

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