func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   const int NAX = 2e5 + 5, MOD = 1000000007;   struct Node {     set<pair<int, int>> vals;     Node() {}     Node lazylazyMerge(const Node &rhs) {}     Node seglazyMerge(const Node &rhs, const int &l, const int &r) {}     Node segSegMerge(const Node &rhs) {}   };   template <typename segNode>   struct Segtree {     vector<segNode> Seg, Lazy;     vector<segNode> Base;     vector<bool> isLazy;     int n;     Segtree(int _n = 2e5) {       this->n = _n;       Seg.resize(4 * _n + 10);       Lazy.resize(4 * _n + 10);       isLazy.resize(4 * _n + 10);     }     void merge(segNode &curr, segNode &l, segNode &r) { curr = l + r; }     void propagate(int node, int L, int R) {       if (isLazy[node]) {         isLazy[node] = false;         Seg[node] = Seg[node].seglazyMerge(Lazy[node], L, R);         if (L != R) {           Lazy[2 * node] = Lazy[2 * node].lazylazyMerge(Lazy[node]);           Lazy[2 * node + 1] = Lazy[2 * node + 1].lazylazyMerge(Lazy[node]);           isLazy[2 * node] = true;           isLazy[2 * node + 1] = true;         }         Lazy[node] = segNode();       }     }     void build(int node, int start, int end) {       if (start == end) {         Seg[node] = Base[start];         return;       }       int mid = (start + end) / 2;       build(2 * node, start, mid);       build(2 * node + 1, mid + 1, end);       Seg[node] = Seg[2 * node].segSegMerge(Seg[2 * node + 1]);     }     void build(vector<segNode> &Arr) {       Base = Arr;       n = Arr.size();       Seg.resize(4 * n + 10);       Lazy.resize(4 * n + 10);       isLazy.resize(4 * n + 10);       build(1, 0, n - 1);     }     pair<int, int> Query(int node, int start, int end, int qstart, int qend) {       propagate(node, start, end);       if (qend < start || qstart > end || start > end)         return pair<int, int>(MOD, MOD);       if (qstart <= start && end <= qend) {         if ((Seg[node].vals).empty()) return pair<int, int>(MOD, MOD);         return *((Seg[node].vals).begin());       }       int mid = (start + end) / 2;       auto l = Query(2 * node, start, mid, qstart, qend);       auto r = Query(2 * node + 1, mid + 1, end, qstart, qend);       return min(l, r);     }     segNode qQuery(int node, int start, int end, int pos) {       propagate(node, start, end);       if (start == end) return Seg[node];       int mid = (start + end) / 2;       if (pos <= mid) return qQuery(2 * node, start, mid, pos);       return qQuery(2 * node + 1, mid + 1, end, pos);     }     void Update(int node, int start, int end, int qstart, int qend, segNode val) {       propagate(node, start, end);       if (qend < start || qstart > end || start > end) return;       if (qstart <= start && end <= qend) {         isLazy[node] = true;         Lazy[node] = val;         propagate(node, start, end);         return;       }       int mid = (start + end) / 2;       Update(2 * node, start, mid, qstart, qend, val);       Update(2 * node + 1, mid + 1, end, qstart, qend, val);       Seg[node] = Seg[2 * node].segSegMerge(Seg[2 * node + 1]);     }     void pUpdate(int node, int start, int end, int pos, pair<int, int> val) {       Seg[node].vals.insert(val);       if (start == end) {         return;       }       int mid = (start + end) / 2;       if (pos <= mid)         pUpdate(2 * node, start, mid, pos, val);       else         pUpdate(2 * node + 1, mid + 1, end, pos, val);     }     void pdel(int node, int start, int end, int pos, pair<int, int> val) {       Seg[node].vals.erase(val);       if (start == end) {         return;       }       int mid = (start + end) / 2;       if (pos <= mid)         pdel(2 * node, start, mid, pos, val);       else         pdel(2 * node + 1, mid + 1, end, pos, val);     }     segNode query(int pos) { return qQuery(1, 0, n - 1, pos); }     pair<int, int> query(int left, int right) {       return Query(1, 0, n - 1, left, right);     }     void update(int pos, pair<int, int> val) { pUpdate(1, 0, n - 1, pos, val); }     void update(int start, int end, segNode val) {       Update(1, 0, n - 1, start, end, val);     }   };   void solveCase() {     int n;     cin >> n;     ;     vector<pair<pair<int, int>, pair<int, pair<int, int>>>> a(n);     vector<int> ranges;     for (size_t i = 0; i < n; i++) {       cin >> a[i].first.first >> a[i].first.second;       cin >> a[i].second.first >> a[i].second.second.first;       a[i].second.second.second = i;       ranges.push_back(a[i].first.first);       ranges.push_back(a[i].second.first);     }     sort(ranges.begin(), ranges.end());     ranges.erase(unique(ranges.begin(), ranges.end()), ranges.end());     for (size_t i = 0; i < n; i++) {       a[i].first.first =           lower_bound(ranges.begin(), ranges.end(), a[i].first.first) -           ranges.begin();       a[i].second.first =           lower_bound(ranges.begin(), ranges.end(), a[i].second.first) -           ranges.begin();     }     sort(a.begin(), a.end());     ;     vector<int> prev(n, -1), dist(n, MOD);     queue<int> Q;     Segtree<Node> stree(n);     for (size_t i = 0; i < n; i++) {       if (a[i].first.first == 0 && a[i].first.second == 0) {         Q.push(i);         dist[i] = 0;       } else         stree.update(i, {a[i].first.second, i});     }     while (Q.size()) {       auto curr_idx = Q.front();       ;       Q.pop();       int c = a[curr_idx].second.first;       int d = a[curr_idx].second.second.first;       int idx2 = lower_bound(a.begin(), a.end(),                              make_pair(make_pair(c + 1, 0),                                        make_pair(0, make_pair(0, 0)))) -                  a.begin();       --idx2;       ;       while (true) {         auto q = stree.query(0, idx2);         ;         if (q.first > d) break;         int idx = q.second;         Q.push(idx);         dist[idx] = dist[curr_idx] + 1;         prev[idx] = curr_idx;         stree.pdel(1, 0, n - 1, idx, q);       }     };     for (size_t i = 0; i < n; i++) {       if (a[i].second.second.second == (n - 1)) {         if (dist[i] != MOD) {           cout << dist[i] + 1 <<   n ;           vector<int> path;           int curr = i;           while (curr >= 0) {             path.push_back(curr);             curr = prev[curr];           }           for (int i = path.size() - 1; i >= 0; i--) {             cout << a[path[i]].second.second.second + 1 <<    ;           }           cout <<   n ;           return;         }       }     }     cout << -1 <<   n ;   }   int32_t main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t = 1;     ;     for (int i = 1; i <= t; ++i) solveCase();     return 0;   }   