#include <bits/stdc++.h>
using namespace std;
const int DEBUG = 0;
const int MOD = 1000 * 1000 + 3;
mt19937 gen(
    (unsigned)chrono::high_resolution_clock::now().time_since_epoch().count());
#pragma comment(linker, "/STACK:67108864")
int bin_pow(int a, int pow) {
  int res = 1;
  while (pow) {
    if (pow & 1) res = (1LL * res * a) % MOD;
    a = (1LL * a * a) % MOD;
    pow /= 2;
  }
  return res;
}
int calc_inv(int x) { return bin_pow(x, MOD - 2); }
vector<int> gauss(vector<vector<int>> x, vector<int> y) {
  int n = y.size();
  for (int i = 0; i < n; i++) {
    int inv = calc_inv(x[i][i]);
    for (int j = i; j < n; j++) x[i][j] = (1LL * x[i][j] * inv) % MOD;
    y[i] = (1LL * y[i] * inv) % MOD;
    for (int j = i + 1; j < n; j++) {
      int mult = x[j][i];
      for (int k = 0; k < n; k++)
        x[j][k] = (x[j][k] - (1LL * x[i][k] * mult) % MOD + MOD) % MOD;
      y[j] = (y[j] - (1LL * y[i] * mult) % MOD + MOD) % MOD;
    }
  }
  vector<int> ans(n);
  for (int i = n - 1; i >= 0; i--) {
    ans[i] = y[i];
    for (int j = i + 1; j < n; j++)
      ans[i] = (ans[i] - (1LL * ans[j] * x[i][j]) % MOD + MOD) % MOD;
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  vector<vector<int>> x(11, vector<int>(11));
  vector<int> y(11);
  for (int i = 0; i < 11; i++) {
    int t = 1;
    for (int j = 0; j < 11; j++, t = (1LL * t * i) % MOD) x[i][j] = t;
    cout << "? " << i << endl;
    cin >> y[i];
  }
  vector<int> k = gauss(x, y);
  for (int i = 0; i < MOD; i++) {
    int val = 0;
    for (int j = 0, p = 1; j < k.size(); j++, p = (1LL * p * i) % MOD)
      val = (val + (1LL * p * k[j]) % MOD + MOD) % MOD;
    if (val == 0) {
      cout << "! " << i << endl;
      return 0;
    }
  }
  cout << "! -1" << endl;
  return 0;
}
