/in/foo.cc: In function 'int main()':
/in/foo.cc:8:18: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    8 |     if(year%4==0 && year%100!=0 || year%400==0)
      |        ~~~~~~~~~~^~~~~~~~~~~~~~
/in/foo.cc:6:22: warning: unused variable 'day' [-Wunused-variable]
    6 |     int year, month, day;
      |                      ^~~