#include <bits/stdc++.h>
using namespace std;
template <class T>
void checkmin(T &a, T b) {
  if (b < a) a = b;
}
template <class T>
void checkmax(T &a, T b) {
  if (b > a) a = b;
}
const int INF = 0x3F3F3F3F;
const long long MOD = 1000003;
const int N = 11;
long long A[N][N], b[N];
void addmod(long long &a, long long b, long long m) {
  if ((a += b) >= m) a -= m;
}
long long mulmod(long long a, long long b, long long m) {
  long long ans = 0;
  a %= m;
  b %= m;
  while (b > 0) {
    if (b & 1) addmod(ans, a, m);
    addmod(a, a, m);
    b /= 2;
  }
  return ans;
}
long long extgcd_mod(long long x, long long y, long long *px, long long *py,
                     long long mod) {
  if (y == 0) {
    *px = 1 % mod;
    *py = 0;
    return x;
  }
  long long g = extgcd_mod(y, x % y, py, px, mod);
  addmod(*py, mod - mulmod(x / y % mod, *px, mod), mod);
  return g;
}
long long get_rev(long long a, long long m) {
  long long pa = 0, pm = 0;
  long long g = extgcd_mod(a, m, &pa, &pm, m);
  assert(g == 1LL);
  return pa;
}
bool solve() {
  for (int r = 0; r < (N); ++r) {
    if (A[r][r] == 0) {
      int r2 = r + 1;
      while (r2 < N && A[r2][r] == 0) ++r2;
      if (r2 >= N) return false;
      for (int j = (r); j <= (N - 1); ++j) swap(A[r][j], A[r2][j]);
      swap(b[r], b[r2]);
    }
    long long mul = get_rev(A[r][r], MOD);
    for (int j = (r); j <= (N - 1); ++j) A[r][j] = A[r][j] * mul % MOD;
    b[r] = b[r] * mul % MOD;
    for (int r2 = 0; r2 < (N); ++r2) {
      if (r2 == r || A[r2][r] == 0) continue;
      mul = MOD - A[r2][r];
      for (int j = (r); j <= (N - 1); ++j)
        A[r2][j] = (A[r2][j] + A[r][j] * mul) % MOD;
      b[r2] = (b[r2] + b[r] * mul) % MOD;
    }
  }
  return true;
}
bool check(long long x) {
  long long ret = b[0], f = 1;
  for (int i = (1); i <= (N - 1); ++i) {
    f = f * x % MOD;
    ret = (ret + f * b[i]) % MOD;
  }
  return ret == 0;
}
int main(int argc, char *argv[]) {
  int ans = -1;
  for (int i = 0; i < (N); ++i) {
    A[i][0] = 1;
    for (int j = (1); j <= (N - 1); ++j) A[i][j] = A[i][j - 1] * i % MOD;
    printf("? %d\n", i);
    fflush(stdout);
    int xq;
    scanf("%d", &xq);
    b[i] = xq;
    if (xq == 0) ans = i;
  }
  if (ans == -1) {
    if (!solve()) {
      printf("! -1\n");
    } else {
      for (int i = 0; i < (MOD); ++i)
        if (check(i)) ans = i;
      printf("! %d\n", ans);
    }
  } else {
    printf("! %d\n", ans);
    fflush(stdout);
  }
}
