Subsets

#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <iostream>
#include <cmath>
#include <sstream>
#include <map>
#include <set>
#include <numeric>
#include <memory.h>
#include <cstdio>
#include <assert.h>

using namespace std;

#define pb push_back
#define INF 1011111111
#define FOR(i, a, b) for (int _n(b), i(a); i < _n; i++)
#define rep(i, n) FOR(i, 0, n)
#define CL(a, v) memset((a), (v), sizeof(a))
#define mp make_pair
#define X first
#define Y second
#define all(c) (c).begin(), (c).end()
#define SORT(c) sort(all(c))

typedef long long ll;
typedef vector<int> VI;
typedef pair<int, int> pii;

/*** TEMPLATE CODE ENDS HERE */

const int maxn = (1 << 17) + 10;
int trie[maxn][2];
int sum[maxn];
int tail[16];

int trie2[maxn][2];
int sum2[maxn];

void increment(int x, int by, int tr[maxn][2], int sm[maxn], int &size) {
  int at = 0;
  for (int i = 15; i >= 0; --i) {
    int bt = (x >> i) & 1;
    if (tr[at][bt] == -1) {
      tr[at][bt] = size++;
    }
    at = tr[at][bt];
    sm[at] += by;
  }
}

int dfs(int at, int x, int pos, int tr[maxn][2], int sm[maxn]) {
  if (at == -1) {
    return 0;
  }
  if (pos == -1) {
    return sm[at];
  }
  if (at && (x & tail[pos]) == tail[pos]) {
    return sm[at];
  }
  int bt = (x >> pos) & 1;
  int s = 0;
  rep(i, 2) {
    if ((i & bt) == i) {
      s += dfs(tr[at][i], x, pos - 1, tr, sm);
    }
  }
  return s;
}

int reverse(int x) {
  int y = 0;
  for (int i = 0; i <= 15; ++i) {
    y |= ((x >> i) & 1) << (15 - i);
  }
  return y;
}

int main() {
#ifdef LOCAL_HOST
  freopen("input.txt", "r", stdin);
// freopen("output.txt","w",stdout);
#endif

  CL(trie, -1);
  rep(i, 17) if (i) tail[i - 1] = (1 << i) - 1;
  CL(trie2, -1);

  int Q;
  scanf("%d", &Q);

  char s[16];
  int x;
  int size = 1;
  int size2 = 1;

  while (Q--) {
    scanf("%s %d", s, &x);
    if (s[0] == 'a') {
      increment(x, 1, trie, sum, size);
      x = reverse(x);
      increment(x, 1, trie2, sum2, size2);
    } else if (s[0] == 'd') {
      increment(x, -1, trie, sum, size);
      x = reverse(x);
      increment(x, -1, trie2, sum2, size2);
    } else {
      int y = reverse(x);
      int cx = 0, cy = 0;
      rep(i, 15) {
        if ((x & tail[i]) == tail[i]) {
          cx = i;
        }
        if ((y & tail[i]) == tail[i]) {
          cy = i;
        }
      }
      if (cx >= cy) {
        int s = dfs(0, x, 15, trie, sum);
        printf("%d\n", s);
      } else {
        int s = dfs(0, y, 15, trie2, sum2);
        printf("%d\n", s);
      }
    }
  }

#ifdef LOCAL_HOST
  printf("TIME: %.3lf\n", double(clock()) / CLOCKS_PER_SEC);
#endif

  return 0;
}