#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
//#include<bits/extc++.h>
//__gnu_pbds
struct seg{
int l;
int r;
int ind;
};
vector<seg> arr;
vector<int> f[20];
int n;
int getcnt(int l,int r){
int cur = l;
int cnt = 0;
for(int p=19;p>=0;p--){
if(f[p][cur]<=r){
cnt+=(1<<p);
cur = f[p][cur];
}
}
return cnt;
}
int main(){
ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
int K;cin>>n>>K;
arr.resize(n+1);
vector<int> d;
for(int i=1;i<=n;i++){
int a,b;cin>>a>>b;
arr[i].l = a;
arr[i].r = b;
arr[i].ind = i;
d.push_back(a);
d.push_back(b);
}
sort(d.begin(),d.end());
d.resize(unique(d.begin(),d.end())-d.begin());
int D = d.size();
for(int i=0;i<20;i++) f[i].resize(D+1,0);
vector<int> ord;
for(int i=1;i<=n;i++) ord.push_back(i);
for(int i=1;i<=n;i++){
arr[i].l = lower_bound(d.begin(),d.end(),arr[i].l)-d.begin()+1;
arr[i].r = lower_bound(d.begin(),d.end(),arr[i].r)-d.begin()+1;
}
sort(ord.begin(),ord.end(),[&](const int &a,const int &b){return arr[a].l>arr[b].l;});
{
int head = 0;
int minn = 1e9;
for(int i=D;i>=1;i--){
while(head<n && arr[ord[head]].l>=i){
minn = min(minn,arr[ord[head]].r);
head++;
}
f[0][i] = minn;
}
}
for(int p=1;p<20;p++){
for(int i=1;i<=D;i++){
if(f[p-1][i]>D) f[p][i]=1e9;
else f[p][i] = f[p-1][f[p-1][i]];
}
}
int allcnt = getcnt(1,D);
map<int,int> aval;
aval[1]=D;
for(int i=1;i<=n;i++){
if(K==0) break;
int l = arr[i].l;
int r = arr[i].r;
if(aval.empty()) continue;
auto it = aval.upper_bound(l);
if(it==aval.begin()) continue;
else --it;
if(it->second<r) continue;
int icnt = allcnt;
icnt-=getcnt(it->first,it->second);
icnt+=getcnt(it->first,l);
icnt+=getcnt(r,it->second);
if(icnt+1>=K){
cout<<i<<"\n";
int L = it->first;
int R = it->second;
aval.erase(it);
aval.insert({L,l});
aval.insert({r,R});
allcnt = icnt;
K--;
}
}
if(K){
cout<<-1<<"\n";
}
return 0;
}
