#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<time.h>
#include<random>
#include<array>
using namespace std;
using ll = long long;
#define rep(i, a, b) for(int i = a; i < b; i++)
#define rrep(i, a, b) for(int i = b - 1; i >= a; i--)
#define ALL(a) a.begin(), a.end()
using pii = pair<int,int>;
using piii = pair<pii,int>;
using pll = pair<long long, long long>;
using plll = pair<pll, long long>;
// #pragma GCC optimize("Ofast")
#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)
#define pb push_back
#define mp make_pair
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );
#define isSquare(x) (sqrt(x)*sqrt(x) == x)
template<class T>inline bool chmax(T &a, const T &b) {if(a<b){a = b; return 1;} return 0; };
template<class T>inline bool chmin(T &a, const T &b) {if(a>b){a = b; return 1;} return 0; };
inline void in(void){return;}
template <typename First, typename... Rest> void in(First& first, Rest&... rest){cin >> first;in(rest...);return;}
inline void out(void){cout << "\n";return;}
template <typename First, typename... Rest> void out(First first, Rest... rest){cout << first << " ";out(rest...);return;}
const double EPS = 1e-9;
const int mod = 1e9 + 7;
// const int mod = 998244353;
const int INF = 1e9;
const long long INFLL = 1e18;
void iosetup() {
    cin.tie(nullptr);ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
}
template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 >& p) {
    os << p.first << " " << p.second;
    return os;
}
template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
    is >> p.first >> p.second;
    return is;
}
template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
    for(int i = 0; i < (int) v.size(); i++) {
        os << v[i] << (i + 1 != v.size() ? " " : "");
    }
    return os;
}
template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
    for(T &in : v) is >> in;
    return is;
}
template<class T> vector<T> make_vec(size_t a) {return vector<T>(a); }
template<class T, class... Ts> auto make_vec(size_t a, Ts... ts){
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}
template<class S, class T> pair<S,T> operator+(const pair<S,T> &s, const pair<S, T>& t){return pair<S,T>(s.first+t.first, s.second+t.second);}
template<class S, class T> pair<S,T> operator-(const pair<S,T> &s, const pair<S, T>& t){return pair<S,T>(s.first-t.first, s.second-t.second);}
template<class S, class T> pair<S,T> operator*(const pair<S,T> &s, const S& t){return pair<S,T>(s.first*t, s.second*t);}
template <typename T> void Exit(T first){cout << first << endl;exit(0); };
template< int mod > struct ModInt {
    unsigned x; ModInt() : x(0) {}
    ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
    ModInt &operator+=(const ModInt &p) {if((x += p.x) >= mod) x -= mod;return *this;}
    ModInt &operator-=(const ModInt &p) {if((x += mod - p.x) >= mod) x -= mod;return *this;}
    ModInt &operator*=(const ModInt &p) {x = (int) (1LL * x * p.x % mod);return *this;}
    ModInt &operator/=(const ModInt &p) {*this *= p.inverse();return *this;}
    ModInt operator-() const { return ModInt(-x); }
    ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
    ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
    ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
    ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
    bool operator==(const ModInt &p) const { return x == p.x; }
    bool operator!=(const ModInt &p) const { return x != p.x; }
    ModInt inverse() const {int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); }return ModInt(u);}
    ModInt pow(int64_t n) const {ModInt ret(1), mul(x); while(n > 0) {if(n & 1) ret *= mul;mul *= mul;n >>= 1;}return ret;}
    friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x;}
    friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt< mod >(t); return (is); }
    static int get_mod() { return mod; }
}; using modint = ModInt< mod >;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
const pii dxy[4] = {pii(1,0), pii(0, 1), pii(-1, 0), pii(0, -1)};
bool range(int a, int b, int x){if(a <= x and x < b)return true;else return false;}
bool range(int a, int b, int c, int d, pii p){if(a <= p.first and p.first < b and c <= p.second and p.second < d) return true;else return false;}

// https://drive.google.com/file/d/1GYxjvoEIn_j9i9AEWP5zQ4yyCQCLysrn/view
// 有向グラフの接続行列Bに対し,線形方程式 Bx = c を (必要なら mod 2 で) 解くライブラリ
template<typename T>
struct LinearSystemIncidence{
    struct Edge {
        int id, to; bool fwd;
        Edge(int i, int t, bool f) : id(i), to(t), fwd(f) {}
    };

    int n, m;
    bool mod2;
    vector<T> x;
    vector<bool> seen;
    vector<vector<Edge> > G;

    LinearSystemIncidence(int n, vector<pii> &E, bool mod2 = false) : n(n), m(E.size()), G(n), mod2(mod2){
        rep(i, 0, m){
            G[E[i].first].emplace_back(i, E[i].second, true);
            G[E[i].second].emplace_back(i, E[i].first, false);
        }
    }

    T dfs(vector<T> &c, int u){
        seen[u] = true;
        T res = c[u];
        for(auto& e: G[u]){
            if(seen[e.to]) continue;
            T tmp = dfs(c, e.to);
            if(e.fwd) x[e.id] = tmp;
            else x[e.id] = -tmp;
            res += tmp;
            if(mod2){
                x[e.id] %= 2;
                if(x[e.id] < 0) x[e.id] += 2;
            }
        }
        if(mod2) res %= 2;
        return res;
    }

    pair<bool, vector<T> > solve(vector<T> &c){
        x.assign(m, 0);
        seen.assign(n, false);
        rep(u, 0, n){
            if(seen[u]) continue;
            if(dfs(c, u)) return {false, vector<T>()};
        }
        return {true, move(x)};
    }
};
// vector<pii> es;
// LinearSystemIncidence<int> LSI(n, es, true);
// auto sol = LSI.solve(c);
// if(!sol.first) Exit(-1);
template< typename T >
struct Compress{
    vector< T > xs;

    Compress() = default;

    Compress(const vector< T > &vs){
        add(vs);
    }

    Compress(const initializer_list<vector < T > > &vs){
        for(auto &p: vs) add(p);
    }

    void add(const vector< T > &vs){
        copy(begin(vs), end(vs), back_inserter(xs));
    }

    void add(const T &x){
        xs.emplace_back(x);
    }

    void build(){
        sort(begin(xs), end(xs));
        xs.erase(unique(begin(xs), end(xs)), end(xs));
    }

    vector< int > get(const vector< T > &vs) const{
        vector< int > ret;
        transform(begin(vs), end(vs), back_inserter(ret), [&](const T &x){
            return lower_bound(begin(xs), end(xs), x) - begin(xs);
        });
        return ret;
    }

    int get(const T &x) const{
        return lower_bound(begin(xs), end(xs), x) - begin(xs);
    }
    int hget(const T &x) const{
        return upper_bound(begin(xs), end(xs), x) - begin(xs);
    }

    const T &operator[](int k) const {
        return xs[k];
    }
};
// add(vs): vs内にある座標を全て追加する
// add(x) : 座標xを追加する
// build(): 構築する
// get(vs): vs内にある座標をそれぞれ座標圧縮したものを返す
// get(x) : 座標xを座標圧縮したものを返す
// [k]    :=座標圧縮後のkが示す実際の座標を返す
// Compress<int> comp;
int main(){
    iosetup();
    int n, m; cin >> n >> m;
    vector<pii> P(n); cin >> P;
    sort(ALL(P));
    vector<int> a(n); 
    vector<int> b(n);
    rep(i, 0, n) tie(a[i], b[i]) = P[i];
    vector<int> c(n+1);
    c[0] = b[0];
    rep(i, 1, n) c[i] = b[i] ^ b[i-1];
    c[n] = b[n-1];

    Compress<int> comp;
    comp.add(a);
    vector<pii> es;
    rep(i, 0, m){
        int l, r; cin >> l >> r;
        int tl = comp.get(l);
        int tr = comp.hget(r);
        es.emplace_back(tl, tr);
    }
    LinearSystemIncidence<int> LSI(n+1, es, true);
    auto sol = LSI.solve(c);
    if(!sol.first) Exit(-1);
    vector<int> ans;
    rep(i, 0, m){
        if(sol.second[i]) ans.push_back(i+1);
    }
    cout << ans.size() << endl;
    cout << ans << endl;

    return 0;
}

Measured memory_bytes: 18416