foo.cc: In function 'int main()':
foo.cc:8:34: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    8 |         if(year%400==0||year%4==0&&year%100!=0)
      |                         ~~~~~~~~~^~~~~~~~~~~~~
foo.cc:6:24: warning: unused variable 'day' [-Wunused-variable]
    6 |         int year,month,day;
      |                        ^~~

[Hydro](https://hydro.ac)提供评测服务