/in/foo.cc: In function 'int main()':
/in/foo.cc:49:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(year%4==0&&year%100!=0||year%400==0)
      ~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:52:18: warning: 'sum' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",sum);
                  ^