/in/foo.cc: In function 'void build_t(int)':
/in/foo.cc:47:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  ls.l=fa.l; ls.r=fa.l+fa.r>>1;
                  ~~~~^~~~~
/in/foo.cc: In function 'void todo(int, int, int, int)':
/in/foo.cc:88:7: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  mid=l+r>>1; mid++;
      ~^~