#include <iostream>
#include <vector>
using namespace std;
int Print(int x, int y) {
    cout << x << " " << y << endl;
    if (x == -1 && y == -1) exit(0);
    int z;
    cin >> z;
    if (z == -1) exit(0);
    return z;
}
void trya(int x, int y) {
    if (x >= y) return;
    int mid = (x + y) / 2;
    trya(x, mid);
    trya(mid + 1, y);
    vector<int> v, vv;
    for (int i = mid; i >= x; i--) v.push_back(i);
    for (int i = y; i >= mid + 1; i--) vv.push_back(i);
    int c = x - 1;
    while (!v.empty() && !vv.empty()) {
        int x = v.back(), y = vv.back();
        c++;
        if (x > y) {
            swap(v, vv);
            swap(x, y);
        }
        if (Print(x, y) == 1) {
            v[v.size() - 1] = vv[vv.size() - 1];
            vv.pop_back();
        }
        else v.pop_back();
        if (x > c) {
            Print(c, x);
            for (int &w : v) {
                if (w == c) w = x;
            }
            for (int &w : vv) {
                if (w == c) w = x;
            }
        }
    }
    if (v.size() < vv.size()) swap(v, vv);
    while (!v.empty()) {
        int x = v.back();
        c++;
        v.pop_back();
        if (x > c) {
            Print(c, x);
            for (int &w : v) {
                if (w == c) w = x;
            }
        }
    }
}
int main() {
    int n;
    cin >> n;
    trya(1, n);
    Print(-1, -1);
}