#include using namespace std; void fast_io() { ios::sync_with_stdio(false); std::cin.tie(nullptr); } int query(int x) { cout << "? " << x << endl; int cnt; cin >> cnt; return cnt; } int main() { fast_io(); int n; cin >> n; int l = 0, r = n + 1; int lcnt = 0, rcnt = n - 1; for (int i = 0; i < 10; i++) { if (l + 1 == r) { query(1); continue; } int mid = (l + r) / 2; int c = query(mid); if (c - lcnt < mid - l) { r = mid; rcnt = c; } else { l = mid; lcnt = c; } } assert(l + 1 == r); cout << "Yes " << l << " " << r << endl; }