#include <bits/stdc++.h>
using namespace std;
void printv(vector<vector<long long>> a) {
  for (auto lel : a) {
    for (auto lel2 : lel) {
      cout << lel2 << " ";
    }
    cout << "\n";
  }
  cout << "\n";
}
long long dnc(int base, int power) {
  if (power == 0) return 1;
  if (power % 2 == 0) {
    long long res = dnc(base, power / 2);
    return res * res % 1000003;
  }
  return 1LL * base * dnc(base, power - 1) % 1000003;
}
int gauss(vector<vector<long long>> a, vector<long long>& ans) {
  int n = (int)a.size();
  int m = (int)a[0].size() - 1;
  vector<int> where(m, -1);
  for (int col = 0, row = 0; col < m && row < n; ++col) {
    int sel = row;
    if (a[sel][row] == 0)
      for (int i = row; i < n; ++i)
        if (abs(a[i][col]) > abs(a[sel][col])) sel = i;
    if (abs(a[sel][col]) == 0) continue;
    for (int i = col; i <= m; ++i) swap(a[sel][i], a[row][i]);
    where[col] = row;
    for (int i = 0; i < n; ++i)
      if (i != row) {
        long long c = a[i][col] * dnc(a[row][col], 1000003 - 2) % 1000003;
        for (int j = col; j <= m; ++j) {
          a[i][j] -= a[row][j] * c % 1000003;
          if (a[i][j] < 0) a[i][j] += 1000003;
        }
      }
    ++row;
  }
  ans.assign(m, 0);
  for (int i = 0; i < m; ++i)
    if (where[i] != -1)
      ans[i] = a[where[i]][m] * dnc(a[where[i]][i], 1000003 - 2) % 1000003;
  for (int i = 0; i < n; ++i) {
    long long sum = 0;
    for (int j = 0; j < m; ++j) sum += ans[j] * a[i][j];
    sum %= 1000003;
    if (abs(sum - a[i][m]) > 0) return 0;
  }
  for (int i = 0; i < m; ++i)
    if (where[i] == -1) return 1000000000;
  return 1;
}
mt19937 rng(29);
int main() {
  vector<vector<long long>> v(13);
  int temp, temp2;
  for (temp = 0; temp < 13; temp++) {
    int tanya = rng() % 1000003;
    cout << "? " << tanya << endl;
    int ans;
    cin >> ans;
    int pw = 1;
    for (int temp2 = 0; temp2 < 11; temp2++) {
      v[temp].push_back(pw);
      pw = 1LL * pw * tanya % 1000003;
    }
    v[temp].push_back(ans);
  }
  vector<long long> ans;
  gauss(v, ans);
  for (temp = 0; temp < 1000003; temp++) {
    long long eval = 0;
    long long curpw = 1;
    for (auto lel : ans) {
      eval += curpw * lel % 1000003;
      curpw = curpw * temp % 1000003;
    }
    eval %= 1000003;
    if (eval == 0) {
      cout << "! " << temp << endl;
      return 0;
    }
  }
  cout << "! -1" << endl;
}
