/in/foo.cc: In function 'int IsLeapYear(int)':
/in/foo.cc:5:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(year%4==0&&year%100||year%100==0) return 1;
      ~~~~~~~~~^~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:30:41: error: ISO C++ forbids declaration of 'WeekdayOfTheFirstDay' with no type [-fpermissive]
  WeekdayOfTheFirstDay(int year,int month)
                                         ^