#include <bits/stdc++.h>
using i64 = long long;

int ask(int a, int b) {
  printf("? %d %d\n", a, b);
  fflush(stdout);
  int ret;
  scanf("%d", &ret);
  return ret;
}

int main() {
  int n;
  scanf("%d", &n);
  std::vector<int> cs;
  for (int i = 1; i <= n; i++) cs.push_back(i);
  std::vector<std::vector<int>> wl(n + 1, std::vector<int>(n + 1));
  while (cs.size() > 1) {
    std::vector<int> next;
    for (int i = 1; 2 * i - 1 < cs.size(); i++) {
      int w = ask(cs[2 * i - 2], cs[2 * i - 1]);
      int l = cs[2 * i - 2] ^ cs[2 * i - 1] ^ w;
      next.push_back(w);
      wl[w][l] = 1;
      wl[l][w] = -1;
    }
    if (cs.size() & 1) next.push_back(cs.back());
    std::swap(next, cs);
  }

  int f = cs.front();
  std::vector<int> cand;
  for (int i = 1; i <= n; i++) if (wl[f][i] > 0) cand.push_back(i);

  while (cand.size() > 1) {
    std::vector<int> next;
    for (int i = 1; 2 * i - 1 < cand.size(); i++) {
      next.push_back(ask(cand[2 * i - 2], cand[2 * i - 1]));
    }
    if (cand.size() & 1) next.push_back(cand.back());
    std::swap(next, cand);
  }

  printf("! %d\n", cand.front());
  fflush(stdout);

  return 0;
}