#include <bits/stdc++.h>
using namespace std;
void fast() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
const long long INFll = 1ll * 1000000000 * 1000000000;
const long double PI =
    3.141592653589793238462643383279502884197169399375105820974944;
int norm(int a) {
  while (a >= 1000003) a -= 1000003;
  while (a < 0) a += 1000003;
  return a;
}
int mul(int a, int b) { return int(a * 1ll * b % 1000003); }
int powmod(int x, int y) {
  int res = 1;
  while (y > 0) {
    if (y & 1) res = mul(res, x);
    x = mul(x, x);
    y = y >> 1;
  }
  return res;
}
int inv(int a) { return powmod(a, 1000003 - 2); }
int query(int x) {
  cout << "? " << x << '\n';
  cout.flush();
  cin >> x;
  return x;
}
void gausselim(vector<vector<int> > &r, vector<int> &a) {
  for (int i = 0; i < int(r.size()); i++) {
    long long pos = -1;
    for (int j = i; j < int(r.size()); j++) {
      if (r[j][i] != 0) {
        pos = j;
        break;
      }
    }
    if (pos == -1) {
      cerr << -1 << '\n';
      continue;
    }
    swap(r[i], r[pos]);
    for (int j = 0; j < int(r.size()); j++) {
      if (i == j) continue;
      int fac = mul(r[j][i], inv(r[i][i]));
      for (int k = i; k < int(r[i].size()); k++) {
        r[j][k] = norm(r[j][k] - mul(fac, r[i][k]));
      }
    }
  }
  for (int i = 0; i < int(a.size()); i++) {
    a[i] = norm(mul(r[i][11], inv(r[i][i])));
  }
}
vector<vector<int> > r(11, vector<int>(12));
int main() {
  vector<int> a(11);
  for (int i = 0; i <= 10; i++) {
    r[i][11] = query(i);
  }
  for (int i = 0; i <= 10; i++) {
    r[i][0] = 1;
    for (int j = 1; j <= 10; j++) {
      r[i][j] = powmod(i, j);
    }
  }
  gausselim(r, a);
  for (int i = 0; i < 1000003; i++) {
    int res = 0;
    for (int j = 10; j >= 0; j--) {
      res = norm(mul(res, i) + a[j]);
    }
    if (res == 0) {
      cout << "! " << i << '\n';
      return 0;
    }
  }
  cout << "! -1" << '\n';
  return 0;
}
