#include <bits/stdc++.h>
using namespace std;
const int mod = 1e6 + 3;
const int N = 1e5 + 9;
inline long long sub(long long a, long long b) {
  a -= b;
  if (a < 0) a += mod;
  return a;
}
inline long long mul(long long a, long long b) {
  a *= b;
  if (a >= mod) a %= mod;
  return a;
}
long long inv[mod + 5], f[13], iv[mod + 5];
signed main() {
  for (int i = 1; i <= 11; i++) {
    cout << "? " << i << endl;
    cin >> f[i];
    if (f[i] == -1) return 1;
  }
  inv[1] = 1;
  for (int i = 2; i < mod; i++) {
    inv[i] = sub(0, mod / i * inv[mod % i] % mod);
  }
  assert(inv[9] * 9 % mod == 1);
  for (int j = 1; j <= 11; j++) {
    long long p = f[j];
    for (int k = 1; k <= 11; k++) {
      if (k != j) {
        p = p * inv[sub(j, k)] % mod;
      }
    }
    iv[j] = p;
  }
  for (int i = 0; i < mod; i++) {
    long long val = 0;
    for (int j = 1; j <= 11; j++) {
      long long p = 1;
      for (int k = 1; k <= 11; k++) {
        if (k != j) {
          p = mul(p, sub(i, k));
        }
      }
      p = mul(p, iv[j]);
      val += p;
      if (val >= mod) val -= mod;
    }
    if (val == 0) {
      cout << "! " << i << endl;
      return 0;
    }
  }
  cout << "! -1" << endl;
  return 0;
  return 0;
}
