#include "minerals.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define y1 zck_is_king
#define pii pair<int, int>
#define ull unsigned ll
#define f first
#define s second
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
#define SQ(x) (x)*(x)
#define MN(a,b) a = min(a,(__typeof__(a))(b))
#define MX(a,b) a = max(a,(__typeof__(a))(b))
#define pb push_back
#define REP(i,n) for (int i = 0; i<n; ++i)
#define RREP(i,n) for (int i = n-1; i>=0; --i)
#define RREP(i,n) for (int i = n-1; i>=0; --i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#ifdef BALBIT
#define IOS()
#define bug(...) fprintf(stderr,"#%d (%s) = ",__LINE__,#__VA_ARGS__),_do(__VA_ARGS__);
template<typename T> void _do(T &&x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S &&...y){cerr<<x<<", ";_do(y...);}
#else
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0);
#define endl '\n'
#define bug(...)
#endif
const int iinf = 1e9+10;
const ll inf = 1ll<<60;
const ll mod = 1e9+7 ;
void GG(){cout<<"0\n"; exit(0);}
ll mpow(ll a, ll n, ll mo = mod){ // a^n % mod
ll re=1;
while (n>0){
if (n&1) re = re*a %mo;
a = a*a %mo;
n>>=1;
}
return re;
}
ll inv (ll b, ll mo = mod){
if (b==1) return b;
return (mo-mo/b) * inv(mo%b,mo) % mo;
}
const int maxn = 1e5+5;
namespace {
bool in[maxn]; // 0-based
int to[maxn]; // to[A] = B => g1[A] matches with g2[B]
int lst = 0;
int QU(int x) {
in[x] ^= 1;
return lst = Query(x+1);
}
};
void gogo(vector<int> a, vector<int> b) {
assert(SZ(b) == SZ(a));
bug(SZ(b));
// bug(l,r);
// for (int x : a) cout<<x<<' ';
// cout<<endl;
int m = SZ(a);
if (SZ(a) == 1) {
to[a[0]] = b[0];
return;
}
int mid = m/2;
int a0=0, a1=0, b0=0, b1=0;
REP(i, m) {
++ (in[a[i]]?a1:a0);
}
REP(i, m) {
if (in[b[i]]) ++b1;
else ++b0;
}
int ais0 = abs(a0-mid) <= abs(a1-mid);
// int bis0 = abs(b0-mid) <= abs(b1-mid);
bool doa = min(abs(a0-mid), abs(a1-mid)) <= min(abs(b0-mid), abs(b1-mid));
if (!doa) {
gogo(b,a);
return;
}
bool targ = 0;
if (ais0) {
targ = a0>mid?0:1;
}else{
targ = a1>mid?1:0;
}
REP(i, m) {
bug(i, a1, a0, mid, in[a[i]], ais0, targ);
if (a1 == mid || a0 == mid) break;
if (in[a[i]] != targ) {
// don't do stuff
}else{
bug("YO");
-- (in[a[i]]?a1:a0);
QU(a[i]);
++ (in[a[i]]?a1:a0);
}
}
vector<int> A0, A1;
REP(i,m) {
(in[a[i]]?A1:A0).pb(a[i]);
}
bug(SZ(A0), SZ(A1), mid);
vector<int> B0, B1;
for (int i = 0; i<SZ(b); ++i) {
if (SZ(B0) == SZ(A0) || SZ(B1) == SZ(A1)) {
if (SZ(B0) < SZ(A0)) {
B0.pb(b[i]);
}
else {
B1.pb(b[i]);
}
continue;
}
int pv = lst;
bool inset = QU(b[i]) == pv;
if (inset) {
B1.pb(b[i]);
// bug(a[i], "going right");
}else{
B0.pb(b[i]);
// bug(a[i], "going left");
}
}
assert(SZ(B0) == SZ(A0) && SZ(B1) == SZ(A1));
gogo(A0,B0); gogo(A1,B1);
}
void Solve(int N) {
srand(time(0));
vector<int> g1, g2; // group 1, group 2, each is a permutation
int prv = 0;
REP(i,N*2) {
if (QU(i) != prv) {
++prv; g1.pb(i);
}else{
g2.pb(i);
}
}
#ifdef BALBIT
for (int x : g1) cout<<x<<' ';
cout<<endl;
for (int x : g2) cout<<x<<' ';
cout<<endl;
#endif // BALBIT
memset(to, -1, sizeof to);
// now, everything is inside the mineral machine
// bool inside = 1;
//
// RREP(bit, 16) {
// // which bit do I care about?
// int needmove = 0;
// REP(i,N) {
// if (((i>>bit)&1) ^ in[g2[i]]) {
// ++needmove; // need to move if
// }
// }
// bool flp = 0;
// if (N-needmove < needmove) {
// flp = 1;
// }
// REP(i,N) {
// if (((i>>bit)&1) ^ flp ^ in[g2[i]]) {
// QU(g2[i]);
// }
// }
//
// REP(i,N) {
// int tmp = lst;
// if ((QU(g1[i]) != tmp) ^ flp ^ 1) {
// // this is inside the set of g2
// to[i] += (1<<bit);
// } // remove it
// }
// }
// vector<int> st(N);
// REP(i,N) st[i] = i;
gogo(g1,g2);
REP(i,N*2) {
bug(i, to[i]);
}
REP(i,N*2) {
if (to[i] != -1) {
Answer(1+i, 1+to[i]);
}
}
}
/*
4
1 5
2 6
3 4
7 8
*/
