#pragma region template
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vld = vector<ld>;
using vvld = vector<vld>;
using vvvld = vector<vvld>;
using vs = vector<string>;
using pll = pair<ll, ll>;
using vp = vector<pll>;
template <typename T>
using pqrev = priority_queue<T, vector<T>, greater<T>>;
#define rep(i, n) for (ll i = 0, i##_end = (n); i < i##_end; i++)
#define repb(i, n) for (ll i = (n)-1; i >= 0; i--)
#define repr(i, a, b) for (ll i = (a), i##_end = (b); i < i##_end; i++)
#define reprb(i, a, b) for (ll i = (b)-1, i##_end = (a); i >= i##_end; i--)
#define ALL(a) (a).begin(), (a).end()
#define SZ(x) ((ll)(x).size())
//*
constexpr ll MOD = 1e9 + 7;
/*/
constexpr ll MOD = 998244353;
//*/
constexpr ll INF = 1e+18;
constexpr ld EPS = 1e-12L;
constexpr ld PI = 3.14159265358979323846L;
constexpr ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; }
constexpr ll LCM(ll a, ll b) { return a / GCD(a, b) * b; }
template <typename S, typename T>
inline bool chmax(S &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename S, typename T>
inline bool chmin(S &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
#ifdef OJ_LOCAL
#include "dump.hpp"
#else
#define dump(...) ((void)0)
#endif
template <typename T>
bool print_(const T &a) {
  cout << a;
  return true;
}
template <typename T>
bool print_(const vector<T> &vec) {
  for (auto &a : vec) {
    cout << a;
    if (&a != &vec.back()) {
      cout << " ";
    }
  }
  return false;
}
template <typename T>
bool print_(const vector<vector<T>> &vv) {
  for (auto &v : vv) {
    for (auto &a : v) {
      cout << a;
      if (&a != &v.back()) {
        cout << " ";
      }
    }
    if (&v != &vv.back()) {
      cout << "\n";
    }
  }
  return false;
}
void print() { cout << "\n"; }
template <typename Head, typename... Tail>
void print(Head &&head, Tail &&... tail) {
  bool f = print_(head);
  if (sizeof...(tail) != 0) {
    cout << (f ? " " : "\n");
  }
  print(forward<Tail>(tail)...);
}
#pragma endregion

// v1をソートし、v2を対応する位置に移動する
template <typename T, typename U>
void pairSort(vector<T> &v1, vector<U> &v2, bool rev = false) {
  int n = v1.size();
  vector<pair<T, U>> p(n);
  for (int i = 0; i < n; i++) {
    p[i] = pair<T, U>(v1[i], v2[i]);
  }
  if (rev) {
    sort(p.begin(), p.end(), [&](const auto &l, const auto &r) {
      if (l.first == r.first)
        return l.second > r.second;
      else
        return l.first < r.first;
    });
  } else {
    sort(p.begin(), p.end());
  }
  for (int i = 0; i < n; i++) {
    v1[i] = p[i].first;
    v2[i] = p[i].second;
  }
}

template <typename T, typename U, typename V>
void tupleSort(vector<T> &v1, vector<U> &v2, vector<V> &v3) {
  int n = v1.size();
  vector<tuple<T, U, V>> p(n);
  for (int i = 0; i < n; i++) {
    p[i] = tuple<T, U, V>(v1[i], v2[i], v3[i]);
  }
  sort(p.begin(), p.end());
  for (int i = 0; i < n; i++) {
    tie(v1[i], v2[i], v3[i]) = p[i];
  }
}

template <typename T>
struct Edge {
  int from, to;
  T cost;
  int id;
  Edge(int from_, int to_, T cost_, int id_) : from(from_), to(to_), cost(cost_), id(id_) {}
  Edge(int from_, int to_, T cost_) : from(from_), to(to_), cost(cost_) {}
  Edge(int from_, int to_) : from(from_), to(to_), cost(1) {}
  bool operator<(const Edge<T> &r) {
    return cost < r.cost;
  }
};
template <typename T>
ostream &operator<<(ostream &os, Edge<T> edge) {
  os << edge.from << " -> " << edge.to << " (" << edge.cost << ")";
  return os;
}

// グラフテンプレート(隣接リスト)
template <typename E = Edge<ll>>
struct GraphL {
  // 頂点数、辺数
  int n, m;
  // 隣接リスト
  vector<vector<E>> adj;
  GraphL(int n_)
      : n(n_), m(0), adj(n_) {}

  template <typename... Args>
  void add_edge(int from, int to, Args... args) {
    adj[from].emplace_back(from, to, args...);
    m++;
  }
  vector<E> &operator[](int i) { return adj[i]; }
};
template <typename E = Edge<ll>>
ostream &operator<<(ostream &os, GraphL<E> graph) {
  os << "V = " << graph.n << ", E = " << graph.m << "\n";
  for (const auto &ev : graph.adj) {
    for (const auto &e : ev) {
      os << e << "\n";
    }
  }
  return os;
}

vll ans;
// 深さ優先探索
template <typename E>
void dfs(GraphL<E> &graph, vll& b) {
  vector<bool> visited(graph.n, false);
  auto dfs_in = [&](auto &Self, int node) -> ll {
    ll ret = 0;
    ret += b[node];
    visited[node] = true;
    for (auto &&e : graph.adj[node]) {
      if (!visited[e.to]) {
        ll tmp = Self(Self, e.to);
        ret += tmp;
        if(tmp % 2 == 1){
          ans.emplace_back(e.id);
        }
      }
    }
    return ret;
  };
  for (int i = 0; i < graph.n; i++) {
    if (!visited[i]) {
      dump(i);
      if(dfs_in(dfs_in, i) % 2 == 1){
        print(-1);
        exit(0);
      }
    }
  }
}


int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(20);
  ll n, m;
  cin >> n >> m;
  vll a(n), b(n);
  rep(i, n){
    cin >> a[i] >> b[i];
  }
  n++;
  a.insert(a.begin(), 0);
  b.insert(b.begin(), 0);
  vll l_(m), r_(m);
  rep(i, m){
    cin >> l_[i] >> r_[i];
  }
  vll l, r, recov;
  pairSort(a, b);
  rep(i, m){
    ll x = lower_bound(ALL(a), l_[i]) - a.begin();
    ll y = upper_bound(ALL(a), r_[i]) - a.begin();
    if(x < y){
      l.emplace_back(x-1);
      r.emplace_back(y-1);
      recov.emplace_back(i+1);
    }
  }
  m = SZ(l);
  tupleSort(l, r, recov);
  rep(i, SZ(b)-1){
    b[i] ^= b[i+1];
  }
  dump(b);
  dump(l);
  dump(r);
  dump(recov);
  GraphL<> g(n);
  rep(i, m){
    g.add_edge(l[i], r[i], 1, recov[i]);
    g.add_edge(r[i], l[i], 1, recov[i]);
  }
  dfs(g, b);
  sort(ALL(ans));
  print(SZ(ans));
  print(ans);
}


Measured memory_bytes: 29812