#include <bits/stdc++.h>
using namespace std;

int main() {
    int T;
    pair<int, int> P0, PT;
    cin >> T >> P0.first >> P0.second >> PT.first >> PT.second;
    int l = 0, r = T;
    while (l + 1 < r) {
        int m = (l + r) >> 1, x, y;
        cout << "? " << m << endl;
        cin >> x >> y;
        int d0 = abs(P0.first - x) + abs(P0.second - y), dT = abs(PT.first - x) + abs(PT.second - y);
        if (d0 == dT) {
            cout << "! " << m << endl;
            break;
        } else if (d0 < dT) {
            l = m;
        } else {
            r = m;
        }
    }
    cout << "! " << l << endl;
}