Author has gone out of the stories about Vasiliy, so here is just a formal task description.You are given q queries and a multiset A, initially containing only integer 0. There are three types of queries: "+ x"- add integer x to multiset A. "- x"- erase one occurrence of integer x from multiset A. It's guaranteed that at least one x is present in the multiset A before this query. "? x"- you are given integer x and need to compute the value , i.e. the maximum value of bitwise exclusive OR (also know as XOR) of integer x and some integer y from the multiset A. Multiset is a set, where equal elements are allowed.

Input The first line of the input contains a single integer q (1 \le q \le 200000)- the number of queries Vasiliy has to perform.Each of the following q lines of the input contains one of three characters '+', '-' or '?' and an integer xi (1 \le xi \le 109). It's guaranteed that there is at least one query of the third type.Note, that the integer 0 will always be present in the set A.

Output For each query of the type '?' print one integer- the maximum value of bitwise exclusive OR (XOR) of integer xi and some integer from the multiset A.

After first five operations multiset A contains integers 0, 8, 9, 11, 6 and 1.The answer for the sixth query is integer - maximum among integers , , , and .