foo.cc: In function 'int main()':
foo.cc:23:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   23 |    if(i%4==0 && i%100!=0 || i%400==0)
      |       ~~~~~~~^~~~~~~~~~~
foo.cc:28:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   28 |   if(y1%4==0 && y1%100!=0 || y1%400==0)
      |      ~~~~~~~~^~~~~~~~~~~~
foo.cc:33:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   33 |   if(y2%4==0 && y2%100!=0 || y2%400==0)
      |      ~~~~~~~~^~~~~~~~~~~~

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