#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N, K;
cin >> N >> K;
vector<int> L(N), R(N);
for (int i = 0; i < N; i++) {
cin >> L[i] >> R[i];
}
vector<int> best;
bool found = false;
// brute‐force all subsets via bitmask
// (only works for N up to ~20)
int maxMask = 1 << N;
for (int mask = 0; mask < maxMask; mask++) {
if (__builtin_popcount(mask) != K)
continue;
// collect the chosen indices (1-based)
vector<int> sel;
sel.reserve(K);
for (int i = 0; i < N; i++) {
if (mask & (1 << i))
sel.push_back(i + 1);
}
// check time‐feasibility: sort by start time, then ensure no overlap
vector<pair<int,int>> times;
times.reserve(K);
for (int idx : sel)
times.emplace_back(L[idx-1], R[idx-1]);
sort(times.begin(), times.end());
bool ok = true;
for (int i = 1; i < K; i++) {
// finish of previous must be <= start of next
if (times[i-1].second > times[i].first) {
ok = false;
break;
}
}
if (!ok)
continue;
// if feasible, check lexicographic order of the index list
if (!found || sel < best) {
best = sel;
found = true;
}
}
if (!found) {
cout << "-1\n";
} else {
// best is already in increasing order
for (int x : best)
cout << x << "\n";
}
return 0;
}
