#include <bits/stdc++.h>
using namespace std;
long long maxi = LLONG_MIN;
long long mini = LLONG_MAX;
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;
long long t, i, j, k, n, temp, flag, ans, m;
long long query(long long x) {
  cout << "? " << x << '\n';
  cout.flush();
  cin >> x;
  return x;
}
long long powmod(long long x, long long y) {
  long long res = 1;
  if (x == 0 && y == 0) return 1;
  if (x == 0) return 0;
  while (y > 0) {
    if (y & 1) res = (res * x) % 1000003;
    x = (x * x) % 1000003;
    y /= 2;
  }
  return res;
}
long long gcdExtended(long long a, long long b, long long *x, long long *y) {
  if (a == 0) {
    *x = 0, *y = 1;
    return b;
  }
  long long x1, y1;
  long long gcd = gcdExtended(b % a, a, &x1, &y1);
  *x = y1 - (b / a) * x1;
  *y = x1;
  return gcd;
}
long long modi(long long a, long long m = 1000003) {
  long long x, y;
  long long g = gcdExtended(a, m, &x, &y);
  if (g != 1)
    return -1;
  else {
    long long res = (x % m + m) % m;
    return res;
  }
}
long long norm(long long a) {
  while (a >= 1000003) a -= 1000003;
  while (a < 0) a += 1000003;
  return a;
}
vector<vector<int> > r(11, vector<int>(12));
int main() {
  long long a[11];
  for (i = 0; i <= 10; i++) {
    r[i][11] = query(i);
  }
  for (i = 0; i <= 10; i++) {
    for (j = 0; j <= 10; j++) {
      r[i][j] = powmod(i, j);
    }
  }
  for (i = 0; i <= 10; i++) {
    long long pos = -1;
    for (j = i; j <= 10; j++) {
      if (r[j][i] != 0) {
        pos = j;
        break;
      }
    }
    if (pos == -1) continue;
    swap(r[i], r[pos]);
    for (j = i + 1; j <= 10; j++) {
      long long fac = (r[j][i] * modi(r[i][i])) % 1000003;
      for (k = i; k <= 11; k++) {
        r[j][k] = (r[j][k] - (fac * r[i][k]) % 1000003 + 1000003) % 1000003;
      }
    }
  }
  for (i = 10; i >= 0; i--) {
    long long pre = 0;
    for (j = 10; j > i; j--) {
      pre = (pre + (a[j] * r[i][j]) % 1000003) % 1000003;
    }
    a[i] = (((r[i][11] - pre) % 1000003 + 1000003) % 1000003 * modi(r[i][j])) %
           1000003;
  }
  for (i = 0; i < 1000003; i++) {
    long long res = 0;
    for (j = 0; j <= 10; j++) {
      res = (res + (a[j] * powmod(i, j)) % 1000003 + 1000003) % 1000003;
    }
    if (res == 0) {
      cout << "! " << i << '\n';
      return 0;
    }
  }
  cout << "! -1" << '\n';
  return 0;
}
