#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
#define rep(i,n) for (int i=0; i<(int)(n); ++i)
#define rep1(i,n) for (int i=1; i<(int)(n); ++i)
#define repeq(i,n) for (int i=0; i<=(int)(n); ++i)
#define rep1eq(i,n) for (int i=1; i<=(int)(n); ++i)
#define rrep(i,n) for (int i=(int)(n)-1; i>=0; --i)
#define rrep1(i,n) for (int i=(int)(n)-1; i>0; --i)
#define rrepeq(i,n) for (int i=(int)(n); i>=0; --i)
#define rrep1eq(i,n) for (int i=(int)(n); i>0; --i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using vb = vector<bool>;
template<typename T> using Graph = vector<vector<T>>;
template<typename T> using Spacial = vector<vector<vector<T>>>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int MOD = 1e9+7;
const int MOD2 = 998244353;
const double EPS = 1e-9;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

template<typename T> struct is_pair : false_type{};
template<typename T1, typename T2> struct is_pair<pair<T1, T2>> : true_type{};
template<typename T> struct is_vector : false_type{};
template<typename T> struct is_vector<vector<T>> : true_type{};

template<typename T1, typename T2>
istream &operator >> (istream &istr, pair<T1, T2> &p) {
  istr >> p.first >> p.second;
  return istr;
} 
template<typename T1, typename T2>
ostream &operator << (ostream &ostr, const pair<T1, T2> &p) {
  ostr << p.first << " " << p.second;
  return ostr;
}
template<typename T>
istream &operator >> (istream &istr, vector<T> &vec) {
  for (auto itr = vec.begin(); itr != vec.end(); ++itr) {
    istr >> *itr;
  }
  return istr;
}
template<typename T>
ostream &operator << (ostream &ostr, const vector<T> &vec) {
  if (vec.empty()) return ostr;
  bool vp = is_vector<T>() || is_pair<T>();
  ostr << vec.front();
  for (auto itr = ++vec.begin(); itr != vec.end(); ++itr) {
    ostr << (vp ? "\n" : " ") << *itr;
  }
  return ostr;
}

template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

int modpow(int a, long long n, int mod = MOD) {
  int ret = 1;
  do {
    if (n & 1) ret = 1LL * ret * a % mod;
    a = 1LL * a * a % mod;
  } while (n >>= 1);
  return ret;
}

template<typename T>
T GCD(T a, T b) { return b ? GCD(b, a%b) : a; }
template<typename T>
T LCM(T a, T b) { return a / GCD(a, b) * b; }

template<typename T1, typename T2>
bool CompareBySecond(pair<T1, T2> a, pair<T1, T2> b) {
  return a.second != b.second ? a.second < b.second : a.first < b.first;
}
template<typename T>
bool CompareBySlope(pair<T, T> a, pair<T, T> b) {
// counterclockwise from 12 o'clock direction
  if (a.first * b.first < 0) return a.first < b.first;
  if (a.first == 0) return a.second >= 0 || b.first > 0;
  if (b.first == 0) return b.second < 0 && a.first < 0;
  return a.second * b.first < a.first * b.second;
}


/* -------- <templates end> -------- */


void solve() {
  int n, m; cin >> n >> m;
  vector<pair<int, bool>> bomb(n); cin >> bomb;
  sort(ALL(bomb));
  vi pos(n);
  rep(i,n) pos[i] = bomb[i].first;
  Graph<pii> code(n);
  rep(i,m) {
    int l, r; cin >> l >> r;
    int nl = lower_bound(ALL(pos), l) - pos.begin();
    int nr = upper_bound(ALL(pos), r) - pos.begin();
    if (nl != nr) code[nl].push_back(pii(nr, i));
  }

  vi process(n, -1);
  vector<pii> ncode;
  vb flip(n+1);
  int idx = m;
  bool now = false;

  rep(i,n) {
    now ^= flip[i];
    sort(RALL(code[i]));
    if (now != bomb[i].second) {
      if (code[i].empty()) {
        cout << -1 << endl;
        return;
      }
      process[i] = code[i][0].second;
      now ^= true;
      flip[code[i][0].first].flip();
    }
    rep1(j,code[i].size()) {
      if (code[i][j].first != code[i][j-1].first) {
        code[code[i][j].first].push_back(pii(code[i][0].first, idx++));
        ncode.push_back(pii(code[i][j].second, code[i][0].second));
      }
    }
  }

  vb restore(idx);
  rep(i,n) {
    if (process[i] >= m) {
      restore[ncode[process[i]-m].first].flip();
      restore[ncode[process[i]-m].second].flip();
    } else if (process[i] != -1) {
      restore[process[i]].flip();
    }
  }
  for (int i=idx-1; i>=m; --i) {
    if (restore[i]) {
      restore[ncode[i-m].first].flip();
      restore[ncode[i-m].second].flip();
    }
  }

  vi ans;
  rep(i,m) {
    if (restore[i]) ans.push_back(i+1);
  }
  cout << ans.size() << "\n" << ans << endl;
}


/* -------- <programs end> -------- */


signed main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);
  solve();
  return 0;
}


Measured memory_bytes: 29416