/*______    ||      |    ||ACはこちらへ|    ||      |    || ̄ ̄ ̄ ̄ ̄ ̄ ∧_∧|| (`・ω・|| ( つ||0  uーu*/ #include using namespace std; //output and debug template using V = vector; template ostream& operator<<(ostream& os, const pair& p) { return os << "P(" << p.first << ", " << p.second << ")"; } template ostream& operator<<(ostream& os,const V& v) { os << "["; bool f = false; for (auto d : v) { if (f) os << ", "; f = true; os << d; } return os << "]"; } template ostream& operator<<(ostream& os,const set& s) { os << "{"; bool f = false; for (auto d : s) { if (f) os << ", "; f = true; os << d; } return os << "}"; } template ostream& operator<<(ostream& os, const multiset& s) { os << "{"; bool f = false; for (auto d : s) { if (f) os << ", "; f = true; os << d; } return os << "}"; } template ostream& operator<<(ostream& os, const map& s) { os << "{"; bool f = false; for (auto p : s) { if (f) os << ", "; f = true; os << p.first << ": " << p.second; } return os << "}"; } template void o(const T& a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; } #ifdef LOCAL #define dbg(...) \ do { \ cerr << __LINE__ << " : " << #__VA_ARGS__ << " = "; \ o(__VA_ARGS__); \ cerr << endl; \ } while (false); #else #define dbg(...) #endif // input template void in(T&... a){ (cin >> ... >> a); } template void in(vector& a){ for(auto&& i : a) in(i); } template void in(pair& p){ in(p.first); in(p.second); } template void in(T& a){ cin >> a; } #define rep1(n) for(ll i = 0; i < n; ++i) #define rep2(i, n) for(ll i = 0; i < n; ++i) #define rep3(i, j, n) for(ll i = j; i < n; ++i) #define overload3(a, b, c, e, ...) e #define rep(...) overload3(__VA_ARGS__, rep3, rep2, rep1)(__VA_ARGS__) #define rrep(i,n) for(ll i = n-1;i>=0;--i) #define all(x) (x).begin(),(x).end() #define rall(x) (x).rbegin(),(x).rend() using ll = long long ; using ld = long double; using pa = pair; using t2 = tuple; using tu = tuple; using vi = vector; using vs = vector; using vp = vector; using vvi = vector; using vvp = vector; using vvvi = vector; using v4 = vector; using vt = vector; const ll INF = (1ll << 29); const ll inf = INF*INF; const int dx[4]={1,-1,0,0}; const int dy[4]={0,0,1,-1}; void Yes(bool i = true){ return o(i?"Yes":"No"); } //reversed priority_queue template class prique :public std::priority_queue, std::greater> {}; const ll mod = 998244353; //const ll mod = 1000000007; int main(){ ll n; in(n); vi a(n),ed(n),ans; in(a); map id; set b; rep(i,n){ --a[i]; id[a[i]] = i; b.emplace(i,a[i]); } rep(i,n/2){ auto nit = id.begin(); ll x = (*nit).first,xid = (*nit).second; auto it = b.upper_bound(pa(xid,x)); if(it == b.end()){ ++nit; x = (*nit).first; xid = (*nit).second; it = b.upper_bound(pa(xid,x)); } ll y = (*it).second,yid = (*it).first; ans.push_back(x); ans.push_back(y); id.erase(id.find(x)); id.erase(id.find(y)); b.erase(pa(xid,x)); b.erase(pa(yid,y)); } rep(i,n) cout << ans[i] + 1 << endl; }