/in/foo.cc: In function 'int main()':
/in/foo.cc:16:6: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   m=l+r>>1;
     ~^~
/in/foo.cc:21:5: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  m=l+r>>1;
    ~^~
/in/foo.cc: In function 'bool check(int)':
/in/foo.cc:44:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^