#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#include <boost/multiprecision/cpp_int.hpp>
namespace mp = boost::multiprecision;
int main () {
	ll n, m, l;
	cin >> n >> m >> l;
	ll ng = 0, ok = (ll)1e9 + 1;
	while (abs(ok - ng) > 1) {
		ll mu = (ok + ng) / 2;
		ll x;
		cout << "? " << mu << " 1" << endl;
		cin >> x;
		if (mu == x) {
			ng = mu;
		} else {
			ok = mu;
		}
	}
	mp::cpp_int ml = 1;
	for (int i = 0; i < l; i ++) ml *= m;
	ll ans = 1; n %= ok;
	while (ml) {
		if (ml & 1) {
			ans = (ans * n) % ok;
		}
		ml>>= 1;
		n = (n * n) % ok;
	}
	cout << "! " << ans << endl;
}