foo.cc: In function 'int main()':
foo.cc:14:7: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   14 |   if(b=2)
      |      ~^~
foo.cc:16:22: warning: statement has no effect [-Wunused-value]
   16 |   (a%4==0&&a%100!=0) || (a%400==0);
      |   ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

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