#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000 * 1000 + 3;
int norm(int a) {
  while (a >= MOD) a -= MOD;
  while (a < 0) a += MOD;
  return a;
}
int mul(int a, int b) { return int(a * 1ll * b % MOD); }
int binPow(int a, int k) {
  int ans = 1;
  while (k > 0) {
    if (k & 1) ans = mul(ans, a);
    a = mul(a, a);
    k >>= 1;
  }
  return ans;
}
int inv(int a) { return binPow(a, MOD - 2); }
int k = 10;
vector<int> f;
int main() {
  f.resize(k + 1);
  for (int i = int(0); i < int(int((f).size())); i++) {
    cout << "? " << i << endl;
    cout.flush();
    cin >> f[i];
  }
  vector<vector<int> > mat(int((f).size()), vector<int>(int((f).size()) + 1));
  for (int i = int(0); i < int(int((mat).size())); i++) {
    mat[i][0] = 1;
    mat[i][int((f).size())] = f[i];
    for (int j = int(1); j < int(int((mat[i]).size()) - 1); j++)
      mat[i][j] = mul(mat[i][j - 1], i);
  }
  for (int j = int(0); j < int(int((mat).size())); j++) {
    int nid = -1;
    for (int i = int(j); i < int(int((mat).size())); i++) {
      if (mat[i][j] != 0) {
        nid = i;
        break;
      }
    }
    if (nid == -1) continue;
    swap(mat[j], mat[nid]);
    for (int i = int(0); i < int(int((mat).size())); i++) {
      if (i == j) continue;
      int cf = mul(mat[i][j], inv(mat[j][j]));
      for (int cj = int(j); cj < int(int((mat[i]).size())); cj++)
        mat[i][cj] = norm(mat[i][cj] - mul(cf, mat[j][cj]));
    }
  }
  vector<int> a(int((f).size()), 0);
  for (int i = int(0); i < int(int((a).size())); i++) {
    if (mat[i][i] == 0) continue;
    a[i] = mul(mat[i][int((a).size())], inv(mat[i][i]));
  }
  for (int x0 = int(0); x0 < int(MOD); x0++) {
    int val = 0;
    for (int i = int((a).size()) - 1; i >= 0; i--)
      val = norm(mul(val, x0) + a[i]);
    if (val == 0) {
      cout << "! " << x0 << endl;
      return 0;
    }
  }
  cout << "! -1" << endl;
  return 0;
}
