foo.cc: In function 'int IsLeapYear(int)':
foo.cc:128:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(year%400==0||year%4==0&&year%100!=0)
                  ~~~~~~~~~^~~~~~~~~~~~~
foo.cc: In function 'int DaysOfMonth(int, int)':
foo.cc:286:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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