foo.cc: In function 'int IsLeapYear(int)':
foo.cc:31:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   31 |  if(year%400==0 || year%4==0 && year%100!=0)
      |                    ~~~~~~~~~~^~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:89:17: warning: unused variable 'd' [-Wunused-variable]
   89 |  int year,month,d;
      |                 ^

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