using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Text;
using System.Linq;

using E = System.Linq.Enumerable;

internal partial class Solver {

    struct Edge {
        public int To;
        public int Id;
    }

    public void Run() {
        var n = ni();
        var m = ni();
        var a = new int[n];
        var b = new int[n + 1];
        for (int i = 0; i < n; i++) {
            a[i] = ni();
            b[i] = ni();
        }

        var t = a.Zip(b, (A, B) => new { A, B })
            .OrderBy(x => x.A)
            .ToArray();

        for (int i = 0; i < n; i++) {
            a[i] = t[i].A;
            b[i] = t[i].B;
        }

        var l = new int[m];
        var r = new int[m];
        for (int i = 0; i < m; i++) {
            l[i] = ni();
            r[i] = ni();
        }

        var adj = Enumerable.Range(0, n + 1).Select(_ => new List<Edge>()).ToArray();

        for (int i = n; i >= 1; i--) {
            b[i] = (b[i] - b[i - 1] + 2) % 2;
        }

        for (int i = 0; i < m; i++) {
            var from = LowerBound(a, l[i]);
            var to = UpperBound(a, r[i]);

            if (from == to) continue;

            adj[from].Add(new Edge { To = to, Id = i + 1 });
            adj[to].Add(new Edge { To = from, Id = i + 1 });
        }

        var ans = new List<int>();
        bool ng = false;

        Func<int, int, bool> dfs = null;
        var visited = new bool[n + 1];
        dfs = (pos, parent) => {
            if (visited[pos]) return false;
            visited[pos] = true;
            bool isOn = b[pos] == 1;
            foreach (var e in adj[pos]) {
                if (e.To == parent) continue;
                var used = dfs(e.To, pos);
                if (used) {
                    ans.Add(e.Id);
                    isOn ^= true;
                }
            }

            return isOn;
        };

        for (int i = 0; i <= n; i++) {
            if (visited[i]) continue;
            if (dfs(i, -1)) {
                ng = true;
                break;
            }
        }
        if (ng) cout.WriteLine(-1);
        else {
            ans.Sort();
            cout.WriteLine(ans.Count);
            cout.WriteLine(string.Join(" ", ans));
        }
    }

    public static int LowerBound<T>(IList<T> A, T x) { return LowerBound(A, 0, A.Count, x); }
    public static int LowerBound<T>(IList<T> A, T x, IComparer<T> comparer) { return LowerBound(A, 0, A.Count, x, comparer); }
    public static int LowerBound<T>(IList<T> A, T x, Comparison<T> comp) { return LowerBound(A, 0, A.Count, x, Comparer<T>.Create(comp)); }
    public static int LowerBound<T>(IList<T> A, int start, int end, T x) { return LowerBound(A, start, end, x, Comparer<T>.Default); }
    public static int LowerBound<T>(IList<T> A, int start, int end, T x, Comparison<T> comp) { return LowerBound(A, start, end, x, Comparer<T>.Create(comp)); }
    public static int LowerBound<T>(IList<T> A, int start, int end, T x, IComparer<T> comparer) {
        int lower = start, upper = end - 1;
        int result = end;
        while (lower <= upper) {
            int pos = (lower + upper) >> 1;
            if (comparer.Compare(x, A[pos]) <= 0) {
                result = pos;
                upper = pos - 1;
            } else {
                lower = pos + 1;
            }
        }
        return result;
    }

    public static int UpperBound<T>(IList<T> A, T x) { return UpperBound(A, 0, A.Count, x); }
    public static int UpperBound<T>(IList<T> A, T x, IComparer<T> comparer) { return UpperBound(A, 0, A.Count, x, comparer); }
    public static int UpperBound<T>(IList<T> A, T x, Comparison<T> comp) { return UpperBound(A, 0, A.Count, x, Comparer<T>.Create(comp)); }
    public static int UpperBound<T>(IList<T> A, int start, int end, T x) { return UpperBound(A, start, end, x, Comparer<T>.Default); }
    public static int UpperBound<T>(IList<T> A, int start, int end, T x, Comparison<T> comp) { return UpperBound(A, start, end, x, Comparer<T>.Create(comp)); }
    public static int UpperBound<T>(IList<T> A, int start, int end, T x, IComparer<T> comparer) {
        int lower = start, upper = end - 1;
        int result = end;
        while (lower <= upper) {
            int pos = (lower + upper) >> 1;
            if (comparer.Compare(x, A[pos]) < 0) {
                result = pos;
                upper = pos - 1;
            } else {
                lower = pos + 1;
            }
        }
        return result;
    }
}

// PREWRITEN CODE BEGINS FROM HERE
internal partial class Solver : Scanner {
    public static void Main(string[] args) {
#if LOCAL
        byte[] inputBuffer = new byte[1000000];
        var inputStream = Console.OpenStandardInput(inputBuffer.Length);
        using (var reader = new StreamReader(inputStream, Console.InputEncoding, false, inputBuffer.Length)) {
            Console.SetIn(reader);
            new Solver(Console.In, Console.Out).Run();
        }
#else
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver(Console.In, Console.Out).Run();
        Console.Out.Flush();
#endif
    }

#pragma warning disable IDE0052
    private readonly TextReader cin;
    private readonly TextWriter cout;
#pragma warning restore IDE0052

    public Solver(TextReader reader, TextWriter writer)
        : base(reader) {
        cin = reader;
        cout = writer;
    }
    public Solver(string input, TextWriter writer)
        : this(new StringReader(input), writer) {
    }

#pragma warning disable IDE1006
#pragma warning disable IDE0051
    private int ni() { return checked(NextInt()); }
    private int[] ni(int n) { return NextIntArray(n); }
    private long nl() { return NextLong(); }
    private long[] nl(int n) { return NextLongArray(n); }
    private double nd() { return NextDouble(); }
    private double[] nd(int n) { return NextDoubleArray(n); }
    private string ns() { return Next(); }
    private string[] ns(int n) { return NextArray(n); }
#pragma warning restore IDE1006
#pragma warning restore IDE0051
}

internal static class LinqPadExtension {
    [Conditional("DEBUG")]
    public static void Dump<T>(this T obj) {
#if DEBUG
        LINQPad.Extensions.Dump(obj);
#endif
    }
}

public class Scanner {
    private readonly TextReader Reader;
    private readonly CultureInfo ci = CultureInfo.InvariantCulture;

    private readonly char[] buffer = new char[2 * 1024];
    private int cursor = 0, length = 0;
    private string Token;
    private readonly StringBuilder sb = new StringBuilder(1024);

    public Scanner()
        : this(Console.In) {
    }

    public Scanner(TextReader reader) {
        Reader = reader;
    }

    public int NextInt() { return checked((int)NextLong()); }
    public long NextLong() {
        var s = Next();
        long r = 0;
        int i = 0;
        bool negative = false;
        if (s[i] == '-') {
            negative = true;
            i++;
        }
        for (; i < s.Length; i++) {
            r = r * 10 + (s[i] - '0');
#if DEBUG
            if (!char.IsDigit(s[i])) throw new FormatException();
#endif
        }
        return negative ? -r : r;
    }
    public double NextDouble() { return double.Parse(Next(), ci); }
    public string[] NextArray(int size) {
        string[] array = new string[size];
        for (int i = 0; i < size; i++) {
            array[i] = Next();
        }

        return array;
    }
    public int[] NextIntArray(int size) {
        int[] array = new int[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextInt();
        }

        return array;
    }

    public long[] NextLongArray(int size) {
        long[] array = new long[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextLong();
        }

        return array;
    }

    public double[] NextDoubleArray(int size) {
        double[] array = new double[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextDouble();
        }

        return array;
    }

    public string Next() {
        if (Token == null) {
            if (!StockToken()) {
                throw new InvalidOperationException();
            }
        }
        var token = Token;
        Token = null;
        return token;
    }

    public bool HasNext() {
        if (Token != null) {
            return true;
        }

        return StockToken();
    }

    private bool StockToken() {
        while (true) {
            sb.Clear();
            while (true) {
                if (cursor >= length) {
                    cursor = 0;
                    if ((length = Reader.Read(buffer, 0, buffer.Length)) <= 0) {
                        break;
                    }
                }
                var c = buffer[cursor++];
                if (33 <= c && c <= 126) {
                    sb.Append(c);
                } else {
                    if (sb.Length > 0) break;
                }
            }

            if (sb.Length > 0) {
                Token = sb.ToString();
                return true;
            }

            return false;
        }
    }
}

Measured memory_bytes: 45664