foo.cc: In function ‘int main()’:
foo.cc:13:26: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   13 |                 if(a%4==0&&a%100!=0||a%400==0)
      |                    ~~~~~~^~~~~~~~~~
foo.cc:12:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wdangling-else]
   12 |         if(b==2)
      |           ^