#include <bits/stdc++.h>
#pragma GCC optimize("Ofast", "unroll-loops")
using namespace std;
const int maxn = 1e5 + 5;
const int iinf = 1 << 29;
const long long inf = 1ll << 60;
const long long mod = 1e6 + 3;
void GG() {
  cout << "No\n";
  exit(0);
}
long long inv(long long b) {
  if (b == 1) return 1ll;
  return inv(mod % b) * (mod - mod / b) % mod;
}
struct Mat {
  int n, m;
  vector<vector<long long> > a;
  Mat operator+(const Mat &b) {
    Mat re(n, m);
    for (int i = 0; i < n; i++)
      for (int j = 0; j < m; j++) re.a[i][j] = (a[i][j] + b.a[i][j]) % mod;
    return re;
  }
  Mat operator-(const Mat &b) {
    Mat re(n, m);
    for (int i = 0; i < n; i++)
      for (int j = 0; j < m; j++)
        re.a[i][j] = (a[i][j] - b.a[i][j] + mod) % mod;
    return re;
  }
  Mat operator*(const Mat &b) {
    Mat re(n, m);
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        re.a[i][j] = 0;
        for (int k = 0; k < m; k++) {
          re.a[i][j] += a[i][k] * b.a[k][j];
          re.a[i][j] %= mod;
        }
      }
    }
    return re;
  }
  Mat operator^(long long v) {
    Mat re(n, m);
    Mat pw(n, m, a);
    while (v) {
      if (v & 1) {
        re = re * pw;
      }
      pw = pw * pw;
      v /= 2;
    }
    return re;
  }
  vector<long long> solve(vector<long long> &ext) {
    for (int i = 0; i < (n); i++) {
      long long minv = inv(a[i][i]);
      for (int j = 0; j < (m); j++) {
        a[i][j] *= minv;
        a[i][j] %= mod;
      }
      ext[i] *= minv;
      ext[i] %= mod;
      for (int j = (i + 1); j < (n); j++) {
        long long ml = a[j][i];
        for (int k = (i); k < (m); k++) {
          a[j][k] += mod - ml * a[i][k];
          a[j][k] %= mod;
        }
        ext[j] += mod - ml * ext[i];
        ext[j] %= mod;
      }
    }
    vector<long long> re(n);
    for (int i = (n - 1); i >= 0; i--) {
      for (int j = (i + 1); j < (m); j++) {
        ext[i] -= (re[j] * a[i][j]) % mod;
      }
      ext[i] = (ext[i] % mod + mod) % mod;
      re[i] = ext[i];
    }
    return re;
  }
  Mat(int nn, int mm, vector<vector<long long> > input) {
    n = nn;
    m = mm;
    a.resize(n);
    for (int i = 0; i < n; i++) {
      a[i].resize(m);
      for (int j = 0; j < m; j++) a[i][j] = input[i][j];
    }
  }
  Mat(int nn, int mm) {
    n = nn;
    m = mm;
    a.resize(n);
    for (int i = 0; i < n; i++) {
      a[i].resize(m);
      if (nn != mm) continue;
      for (int j = 0; j < m; j++) {
        if (i == j) a[i][j] = 1;
      }
    }
  }
};
const int BB = 11;
int main() {
  ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  Mat A(BB, BB);
  vector<long long> ext(BB);
  for (int i = 0; i < (BB); i++) {
    long long np = 1;
    cout << "? " << i << endl;
    cin >> ext[i];
    for (int j = 0; j < (BB); j++) {
      A.a[i][j] = np;
      np *= i;
      np %= mod;
    }
  }
  vector<long long> a = A.solve(ext);
  long long pp = 1;
  cout << "! ";
  for (int i = 0; i < (mod); i++) {
    long long re = 0;
    for (int j = (BB - 1); j >= 0; j--) {
      re *= i;
      re += a[j];
      re %= mod;
    }
    if (re == 0) {
      cout << i << endl;
      return 0;
    }
  }
  cout << -1 << endl;
  return 0;
}
