foo.cc: In function 'bool isleap(int)':
foo.cc:5:12: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    5 |  if(n%4==0 && n%100!=0||n%400==0)
      |     ~~~~~~~^~~~~~~~~~~
foo.cc: In function 'int day(int, int)':
foo.cc:19:1: warning: control reaches end of non-void function [-Wreturn-type]
   19 | }
      | ^

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