/in/foo.cc: In function 'int gcd(int, int)':
/in/foo.cc:11:8: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
  if(a&1==0 && b&1==0) 
       ~^~~
/in/foo.cc:11:18: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
  if(a&1==0 && b&1==0) 
                 ~^~~
/in/foo.cc:13:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
  else if(a&1==0)
            ~^~~
/in/foo.cc:15:13: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
  else if(b&1==0)
            ~^~~