#include<bits/stdc++.h>
using namespace std;
const int nax = 2e5 + 3;
const int lg = 20;
int to[nax];
int jt[nax][lg];
int jump(int i, int j) {
if(jt[i][j]!=-1) return jt[i][j];
if(j==0) return jt[i][j] = to[i];
return jt[i][j] = jump(jump(i, j-1), j-1);
}
int get_ans(int l, int r) {
int ret = 0;
for(int i=lg-1; i>=0; --i) {
if(jump(r, i)>=l) {
ret |= 1<<i;
r = jump(r, i);
}
}
return ret;
}
void PlayGround() {
int n, k;
cin>>n>>k;
map<pair<int,int>, int>rg;
map<int,int>h;
for(int i=1; i<=n; ++i) {
int l, r;
cin>>l>>r;
int cr = rg[{l, r}];
if(!cr) {
rg[{l, r}] = i;
h[l] = h[r] = 1;
}
}
int cm = 1;
for(auto &it : h) {
it.second = cm++;
}
for(auto &it : rg) {
auto [l, r] = it.first;
to[h[r]] = max(to[h[r]], h[l]);
}
for(int i=1; i<=2 * n + 1; ++i) {
to[i] = max(to[i], to[i-1]);
}
memset(jt, -1, sizeof jt);
map<int, pair<int,int>>id_to_rg;
for(auto it : rg) {
id_to_rg[it.second] = it.first;
}
int cur = get_ans(1, 2*n + 1);
if(cur < k) {
cout<<"-1\n";
return;
}
set<pair<int,int>>alive = {{2 * n + 1, 1}};
vector<int>ans;
for(auto it : id_to_rg) {
if(ans.size()==k) break;
auto [l, r] = it.second;
l = h[l], r = h[r];
auto rel = *alive.lower_bound(make_pair(r, -1));
if(rel.second<=l) { //can take
int new_ans = cur - get_ans(rel.second, rel.first)
+ get_ans(rel.second, l) + get_ans(r, rel.first);
if(new_ans + ans.size() + 1 >= k) {
ans.push_back(it.first);
cur = new_ans;
alive.erase(rel);
alive.insert({l, rel.second});
alive.insert({rel.first, r});
}
}
}
for(int x : ans) {
cout<<x<<'\n';
}
// cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
PlayGround();
return 0;
}
