#include <bits/stdc++.h>
using namespace std;
const int mod = 1e6 + 3;
void Mod(long long &x) { x = (x % mod + mod) % mod; }
long long pw(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % mod;
    b >>= 1;
    a = a * a % mod;
  }
  return ans;
}
struct LU {
  long long a[100][100];
  long long x[100];
  int h = 0, l = 0, n, m;
  bool flag = false;
  void sol() {
    m = n + 1;
    while (h != n && l != m) {
      h++, l++;
      for (int j = l; j <= m; j++) {
        int t = min(h, j) - 1;
        for (int k = 1; k <= t; k++) {
          a[h][j] -= a[h][k] * a[k][j];
          Mod(a[h][j]);
        }
        if (h > j) a[h][j] *= pw(a[j][j], mod - 2), Mod(a[h][j]);
        if (h > j && a[j][j] == 0) flag = true;
      }
      for (int j = h + 1; j <= n; j++) {
        int t = min(l, j) - 1;
        for (int k = 1; k <= t; k++) {
          a[j][l] -= a[j][k] * a[k][l];
          Mod(a[j][l]);
        }
        if (j > l) a[j][l] *= pw(a[l][l], mod - 2), Mod(a[j][l]);
        if (j > l && a[l][l] == 0) flag = true;
      }
    }
    for (int i = n; i >= 1; i--) {
      x[i] = a[i][m];
      for (int j = i + 1; j <= m - 1; j++) {
        x[i] -= a[i][j] * x[j];
        Mod(x[i]);
      }
      x[i] *= pw(a[i][i], mod - 2);
      Mod(x[i]);
      if (a[i][i] == 0) flag = true;
    }
  }
} lu;
int main() {
  long long t = 1;
  lu.n = 11;
  for (int i = 1; i <= 11; i++) {
    t = 1;
    for (int j = 1; j <= 11; j++) {
      lu.a[i][j] = t;
      t *= (i - 1);
      t %= mod;
    }
  }
  for (int i = 1; i <= 11; i++) {
    printf("? %d\n", i - 1);
    fflush(stdout);
    scanf("%lld", &lu.a[i][12]);
  }
  lu.sol();
  for (int i = 0; i < 1e6 + 3; i++) {
    t = 1;
    long long ans = 0;
    for (int j = 0; j <= 10; j++) {
      ans += t * lu.x[j + 1] % mod;
      ans %= mod;
      t *= i;
      t %= mod;
    }
    if (ans == 0) {
      printf("! %d\n", i);
      fflush(stdout);
      return 0;
    }
  }
  printf("! -1\n");
  return 0;
}
