#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e6 + 3;
long long a[20][20], ans[20];
long long px(long long a, long long q) {
  if (q == 0) return 1;
  long long tmp = px(a, q / 2);
  tmp = (tmp * tmp) % MOD;
  if (q & 1) tmp = (tmp * a) % MOD;
  return tmp;
}
long long gt(long long x, long long q) {
  long long ans = 1;
  for (int i = 1; i <= q; ++i) ans *= x;
  return ans;
}
int main() {
  long long k = 10;
  for (int i = 0; i <= k; ++i) {
    cout << "? " << i << endl;
    for (int j = 0; j <= k; ++j) a[i][j] = gt(i, j) % MOD;
    cin >> a[i][k + 1];
  }
  int column = 0;
  for (int i = 0; i <= k; ++i) {
    for (int j = i; j <= k; ++j)
      if (a[j][column] != 0) {
        swap(a[i], a[j]);
        break;
      }
    for (int j = i + 1; j <= k; ++j) {
      for (int c = k + 1; c > column; --c) {
        a[j][c] = (a[j][c] -
                   a[i][c] * a[j][column] % MOD * px(a[i][column], MOD - 2)) %
                  MOD;
        a[j][c] = (a[j][c] + MOD) % MOD;
      }
      a[j][column] = 0;
    }
    column++;
  }
  ans[k] = a[k][k + 1] * px(a[k][k], MOD - 2) % MOD;
  for (int i = k - 1; i >= 0; --i) {
    for (int j = i + 1; j <= k; ++j)
      a[i][k + 1] = (a[i][k + 1] - ans[j] * a[i][j]) % MOD;
    a[i][k + 1] = (a[i][k + 1] + MOD) % MOD;
    ans[i] = (a[i][k + 1] * px(a[i][i], MOD - 2)) % MOD;
  }
  for (int i = 0; i < 1e6 + 3; ++i) {
    long long sum = 0;
    for (int j = 0; j <= k; ++j)
      sum = (sum + (long long)ans[j] % MOD * px(i, j)) % MOD;
    if (!sum) {
      cout << "! " << i << endl;
      return 0;
    }
  }
  cout << "! -1" << endl;
  return 0;
}
