/in/foo.cc:7:23: warning: multi-character character constant [-Wmultichar]
    7 |                 cout<<'YES';
      |                       ^~~~~
/in/foo.cc:9:23: warning: multi-character character constant [-Wmultichar]
    9 |                 cout<<'NO';
      |                       ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:6:18: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    6 |         if(x%4==0&&x%100!=0||x%400==0)
      |            ~~~~~~^~~~~~~~~~