/in/foo.cc: In function 'int main()':
/in/foo.cc:52:33: warning: suggest parentheses around arithmetic in operand of '|' [-Wparentheses]
      b1.push((b1f-'0')|(b1s-'0')-'0');
                        ~~~~~~~~~^~~~
/in/foo.cc:53:33: warning: suggest parentheses around arithmetic in operand of '|' [-Wparentheses]
      b2.push((b2f-'0')|(b2s-'0')-'0');
                        ~~~~~~~~~^~~~
/in/foo.cc:56:33: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
      b1.push((b1f-'0')^(b1s-'0')-'0');
                        ~~~~~~~~~^~~~
/in/foo.cc:57:33: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
      b2.push((b2f-'0')^(b2s-'0')-'0');
                        ~~~~~~~~~^~~~
/in/foo.cc:60:33: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
      b1.push((b1f-'0')&(b1s-'0')-'0');
                        ~~~~~~~~~^~~~
/in/foo.cc:61:33: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
      b2.push((b2f-'0')&(b2s-'0')-'0');
                        ~~~~~~~~~^~~~