#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

vector<int> Eratosthenes(const int N)
{
    vector<bool> is_prime(N + 1);
    for (int i = 0; i <= N; i++)
    {
        is_prime[i] = true;
    }
    vector<int> P;
    for (int i = 2; i <= N; i++)
    {
        if (is_prime[i])
        {
            for (int j = 2 * i; j <= N; j += i)
            {
                is_prime[j] = false;
            }
            P.emplace_back(i);
        }
    }
    return P;
}

int main()
{
    int n;
    cin >> n;
    vector<int> prime = Eratosthenes(n);
    int ans = 1;
    rep(i, prime.size())
    {
        int ret = 1;
        while (ret * prime[i] * ans <= n)
            ret *= prime[i];
        if (ret != 1)
        {
            cout << "?" << ret << endl;
            int inp;
            cin >> inp;
            ans *= inp;
        }
        else
            break;
    }
    cout << "! " << ans << endl;
}