#include <bits/stdc++.h>
using namespace std;
const long long N = 1e6;
const long long mod = 1e6 + 3;
long long bigmod(long long b, long long p, long long mod) {
  long long ret = 1LL;
  while (p) {
    if (p % 2) ret = (ret * b) % mod;
    b = (b * b) % mod;
    p /= 2;
  }
  return ret;
}
long long inv(long long x) { return bigmod(x, mod - 2, mod); }
void gauss(vector<vector<long long>> a, vector<long long> &ans) {
  long long n = a.size(), m = a[0].size() - 1;
  vector<long long> wh(m, -1);
  for (long long col = 0, row = 0; col < m && row < n; col++) {
    long long swp = -1;
    for (long long i = row; i < n; i++) {
      if (a[i][col]) {
        swp = i;
        break;
      }
    }
    if (swp == -1) continue;
    for (long long i = col; i <= m; i++) swap(a[row][i], a[swp][i]);
    wh[col] = row;
    for (long long i = 0; i < n; i++) {
      if (i == row) continue;
      long long c = (a[i][col] * inv(a[row][col])) % mod;
      for (long long j = 0; j <= m; j++)
        a[i][j] = (a[i][j] - (a[row][j] * c) % mod + mod) % mod;
    }
    row++;
  }
  ans.assign(m, 0);
  for (long long i = 0; i < m; i++) {
    if (wh[i] == -1) continue;
    ans[i] = (a[wh[i]][m] * inv(a[wh[i]][i])) % mod;
  }
}
long long eval(long long x, vector<long long> ans) {
  long long p = 1, sum = 0;
  for (long long i = 0; i <= 10; i++) {
    sum = (sum + p * ans[i]) % mod;
    p = (p * x) % mod;
  }
  return sum;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  vector<vector<long long>> a;
  vector<long long> ans, v;
  for (long long i = 0; i <= 10; i++) {
    v.clear();
    long long p = 1;
    for (long long j = 0; j <= 10; j++) {
      v.push_back(p);
      p = (p * i) % mod;
    }
    cout << "? " << i << endl;
    long long x;
    cin >> x;
    v.push_back(x);
    a.push_back(v);
  }
  gauss(a, ans);
  for (long long i = 0; i < mod; i++) {
    if (!eval(i, ans)) cout << "! " << i << endl, exit(0);
  }
  cout << "! " << -1 << endl;
  return 0;
}
