/in/foo.cc: In function 'int main()':
/in/foo.cc:22:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if (a == 11 && a > b && a - b >= 2 || b == 11 && b > a && b - a >= 2)
       ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:28:29: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   else if (a >= 11 && a > b && a - b >= 2 || b >= 11 && b > a && b - a >= 2)
            ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:45:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if (a == 21 && a > b && a - b >= 2 || b == 21 && b > a && b - a >= 2)
       ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
/in/foo.cc:51:29: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   else if (a >= 21 && a > b && a - b >= 2 || b >= 21 && b > a && b - a >= 2)
            ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~