#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
/*
read the solution a long time ago, remember some key ideas from there
*/
const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
void solve(int test_case)
{
ll n,k; cin >> n >> k;
vector<pll> a(n+5);
rep1(i,n) cin >> a[i].ff >> a[i].ss;
rep1(i,n) a[i].ss--;
set<pll> st;
st.insert({-inf1,-inf1});
auto ok = [&](ll l, ll r){
auto it1 = st.lower_bound({l+1,-1});
it1--;
auto it2 = st.lower_bound({r,-1});
it2--;
if(it1 != it2) return false;
auto [lx,rx] = *it1;
if((lx <= l and l <= rx) or (lx <= r and r <= rx)) return false;
return true;
};
vector<ll> ans;
rep1(i,n){
if(sz(ans) == k) break;
auto [l,r] = a[i];
if(!ok(l,r)) conts;
st.insert({l,r});
vector<pll> segs;
for(int j = i+1; j <= n; ++j){
auto [lx,rx] = a[j];
if(!ok(lx,rx)) conts;
segs.pb({rx,lx});
}
sort(all(segs));
ll prevr = -inf2;
ll cnt = sz(st)-1;
for(auto [rx,lx] : segs){
if(lx > prevr){
cnt++;
prevr = rx;
}
}
if(cnt >= k){
ans.pb(i);
}
else{
st.erase({l,r});
}
}
if(ans.empty()){
cout << -1 << endl;
}
else{
trav(x,ans) cout << x << endl;
}
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
