foo.cc: In function 'int main()':
foo.cc:6:10: error: expected primary-expression before '>' token
    6 |     cin>>>n;
      |          ^
foo.cc:7:22: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    7 |         cout<<(n%4==0&&n%100!=0||n%400==0)?"YES":"NO";
      |                ~~~~~~^~~~~~~~~~
foo.cc:7:44: warning: second operand of conditional expression has no effect [-Wunused-value]
    7 |         cout<<(n%4==0&&n%100!=0||n%400==0)?"YES":"NO";
      |                                            ^~~~~
foo.cc:7:50: warning: third operand of conditional expression has no effect [-Wunused-value]
    7 |         cout<<(n%4==0&&n%100!=0||n%400==0)?"YES":"NO";
      |                                                  ^~~~

[Hydro](https://hydro.ac)提供评测服务