/in/foo.cc: In function 'void build(int, int, int)':
/in/foo.cc:35:59: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  tree[p].x=0;if(l==r){tree[p].x=a[id[l]];return;}int mid=l+r>>1;
                                                          ~^~
/in/foo.cc: In function 'void add(int, int, int, int, int, int)':
/in/foo.cc:40:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
/in/foo.cc: In function 'int ask(int, int, int, int)':
/in/foo.cc:53:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~