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

int n;

int inter(int i, int j){
    if (i == j) return 0;
    if (i > j) swap(i, j);
    cout << i+1 << " " << j+1 << endl;
    int v; cin >> v;
    if (v == -1) exit(0);
    return v;
}

void trip(int pos, int c1, int c2){
    assert(pos < c1 && c1 < c2);
    inter(c1, c2);
    inter(pos, c1);
}

void recurse(int begin, int end){
    if (begin+1 == end) return;

    int mid = (begin + end)>>1;
    recurse(begin, mid);
    recurse(mid, end);

    int ptrl = begin, ptrr = mid;
    while (true){
        int v = inter(ptrl, ptrr);
        ptrl++;
        if (v) break;
        if (ptrl == mid) return;
    }

    while (ptrl != mid){
        trip(ptrl, ptrr, ptrr+1);
        ptrl++;
    }
    
    while (ptrr+1 != end){
        int v = inter(ptrr, ptrr+1);
        if (v == 0) break;
        ptrr++;
    }
}

signed main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    recurse(0, n);
}