/in/foo.cc: In function 'int main()':
/in/foo.cc:8:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
 #define mid (l+r>>1)
              ~^~
/in/foo.cc:53:12: note: in expansion of macro 'mid'
   if(check(mid)>=k) r=mid-1;
            ^~~
/in/foo.cc:8:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
 #define mid (l+r>>1)
              ~^~
/in/foo.cc:53:23: note: in expansion of macro 'mid'
   if(check(mid)>=k) r=mid-1;
                       ^~~
/in/foo.cc:8:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
 #define mid (l+r>>1)
              ~^~
/in/foo.cc:54:10: note: in expansion of macro 'mid'
   else l=mid+1;
          ^~~