#pragma GCC optimize("O3") //#pragma GCC target("avx2") //#pragma GCC optimize("unroll-loops") #include using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef vector vi; typedef vector vll; typedef vector vld; typedef vector vb; typedef pair Pll; typedef pair Pin; ll INF = 1e16; int inf = 1e9; #define ALL(x) (x).begin(), (x).end() #define FOR(i, m, n) for (ll i = (m); i < (n); ++i) #define REVFOR(i, m, n) for (ll i = ((n) - 1); i >= (m); --i) #define REP(i, n) FOR(i, 0, n) #define REVREP(i, n) REVFOR(i, 0, n) #define fi first #define se second #define pb push_back #define mp make_pair #define eb emplace_back #define bcnt __builtin_popcountll // inputs #define VLLIN(x, n) vll x(n); REP(i, n) cin >> x[i]; #define VIIN(x, n) vi x(n); REP(i, n) cin >> x[i]; #define VLDIN(x, n) vld x(n); REP(i, n) cin >> x[i]; #define SIN(s, n) string s; cin >> s; #ifdef LOCAL #include #define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", d_err(__VA_ARGS__); #else #define debug(...) 83; #endif void d_err() { cerr << endl; } template void d_err(H h, T... t) { cerr << h << " "; d_err(t...); } template void print(T x) { cout << x << "\n"; } template void print(vector& x) { int N = x.size(); REP(i, N) { if (i > 0) cout << " "; cout << x[i]; } cout << "\n"; } int ask(int l, int r) { cout << "? " << l << " " << r << endl; int s; cin >> s; return s; } void answer(int l, int r) { cout << "! " << l << " " << r << endl; } int main(){ cin.tie(0); ios_base::sync_with_stdio(false); cout << fixed << setprecision(20); int n; cin >> n; int range = n / 2; if (range & 1) range++; int l = 1, r = n - range + 2; while(r - l > 1) { int m = (l + r) / 2; int s = ask(m, m + range); int diff = range - 2 * s; if (diff == 0) { answer(m, m + range); return 0; } if (diff < 0) { r = m; } else { l = m + 1; } } answer(l, l + range); }