#include<bits/stdc++.h>
using namespace std;
void answer(int x) {
cout << '!' << ' ' << x << endl;
exit(0);
}
int ask(int x) {
cout << '?' << ' ' << x << endl;
int ret;
cin >> ret;
return ret;
}
int n;
int L = 1;
int R = n;
int LST = 0;
void solve(int l, int r, int lst) {
L = l;
R = r;
LST = lst;
if (l + 1 < r) {
} else {
return;
}
int x = ask(r);
if(x == lst) {
answer(r);
}
r --;
int mid = (l + r) >> 1;
int y = ask(mid);
if(y == x) {
answer(mid);
}
if(x < y) {
solve(l, mid - 1, y);
}
//0 1 1
else {
solve(mid + 1, r - 1, y);
}
return;
}
int main() {
cin >> n;
L = 1, R = n;
solve(1, n, 0);
cout << L << ' ' << R << endl;
if (ask(L) == LST) {
LST = answer(L);
} else if (ask(R) == LST){
answer(R);
}
return 0;
}