foo.cc: In function 'int main()':
foo.cc:7:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(a%4==0&&a%100!=0||a%400==0)
     ~~~~~~^~~~~~~~~~
foo.cc:9:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
  else
  ^~~~
foo.cc:11:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   return 0;
   ^~~~~~

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