/in/foo.cc: In function 'int main()':
/in/foo.cc:8:19: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   cout<<28+(y%4==0&&y%100!=0||y%400==0)?1:0;
             ~~~~~~^~~~~~~~~~
/in/foo.cc:8:44: warning: second operand of conditional expression has no effect [-Wunused-value]
   cout<<28+(y%4==0&&y%100!=0||y%400==0)?1:0;
                                            ^
/in/foo.cc:8:44: warning: third operand of conditional expression has no effect [-Wunused-value]