/in/foo.cc: In function 'void create(int, int, int)':
/in/foo.cc:21:10: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  create(o<<1+1,mid+1,r);
          ^
/in/foo.cc:22:41: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  tree[o].maxv=max(tree[o<<1].maxv,tree[o<<1+1].maxv);
                                         ^