#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll INF = 1ll << 60;
#define REP(i, n) for(ll i =0; i < ll(n); i++)
template <class T> using V = vector<T>;
template <class A, class B>
bool chmax(A& a, B b) { return a<b && (a=b, true); }
template <class A, class B>
bool chmin(A& a, B b) { return b<a && (a=b, true); }

void testcase() {
  int n; cin >> n;
  V<int> ten(n);
  ten[0] = 1;
  REP(i, n-1) ten[i+1] = ten[i] * 10;
  V<int> prod(n-1);
  V<int> non_zero;
  REP(i, n-1) {
    cout << "? " << i << ' ' << n-1 << endl;
    cin >> prod[i];
    if(prod[i]) non_zero.push_back(i);
  }
  if(non_zero.size() == 0) {
    cout << "! -1" << endl;
    return;
  }
  if(non_zero.size() == 1) {
    if(prod[non_zero[0]] == 1) {
      cout << "! " << ten[n-1] + ten[non_zero[0]] << endl;
    } else {
      cout << "! -1" << endl;
    }
    return;
  }
  cout << "? " << non_zero[0] << ' ' << non_zero[1] << endl;
  int p; cin >> p;
  int d02 = prod[non_zero[0]] * prod[non_zero[1]] / p;
  int d0 = sqrt(d02);
  assert(d0*d0 == d02);
  int ans = ten[n-1] * d0;
  REP(i, n-1) ans += ten[i] * (prod[i] / d0);
  cout << "! " << ans << endl;
}

int main() {
  // cin.tie(0)->sync_with_stdio(0);
  testcase();
}