#include <bits/stdc++.h> using namespace std; void setup() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); } int n, k, head, num, new_num, a, b; int nxt[20][200000]; array<int, 3> p[200000]; set<pair<int, int>> s; set<pair<int, int>>::iterator it; vector<int> v; inline bool Comp(const array<int, 3> &ina, const array<int, 3> &inb) { return ina[1] < inb[1]; } inline bool Comp1(const array<int, 3> &ina, const array<int, 3> &inb) { return ina[2] < inb[2]; } inline int Count(int ind, int limit) { int ret = 1; if (limit < p[ind][1]) { return 0; } for (int i = 19; i >= 0; --i) { if (nxt[i][ind] != -1 && p[nxt[i][ind]][1] <= limit) { ret += (1 << i); ind = nxt[i][ind]; } } return ret; } int main() { setup(); cin >> n >> k; for (int i = 0; i < n; ++i) { cin >> p[i][0] >> p[i][1]; p[i][2] = i; } sort(p, p + n, Comp); head = p[0][2]; for (int i = 0, j = 0; i < n; ++i) { j = max(i, j); while (j < n && p[j][0] < p[i][1]) { j++; } nxt[0][p[i][2]] = (j == n ? -1 : p[j][2]); } sort(p, p + n, Comp1); for (int i = 1; i < 20; ++i) { for (int j = 0; j < n; ++j) { nxt[i][j] = (nxt[i - 1][j] == -1 ? -1 : nxt[i - 1][nxt[i - 1][j]]); } } num = Count(head, 1e9); for (int i = 0; i < n && s.size() < k; ++i) { s.insert({p[i][1], p[i][2]}); it = s.lower_bound({p[i][1], p[i][2]}); if (it == s.begin()) { a = head; } else { a = (*prev(it)).second; } if (next(it) == s.end()) { b = 1e9; } else { b = (*next(it)).first; } if ((it != s.begin() && p[a][1] > p[i][0]) || (p[i][1] > b)) { s.erase({p[i][1], p[i][2]}); continue; } new_num = num - Count(a, b) + Count(a, p[i][0]) + Count(i, b); if (new_num >= k) { num = new_num; v.push_back(i + 1); continue; } s.erase({p[i][1], p[i][2]}); } if (v.size() < k) { cout << -1; return 0; } for (auto & i : v) { cout << i << "\n"; } return 0; }