Problem: You are given n pairs of integers (a_1, b_1), (a_2, b_2), …, (a_n, b_n). All of the integers in the pairs are distinct and are in the range from 1 to 2 ⋅ n inclusive.

Let's call a sequence of integers x_1, x_2, …, x_{2k} good if either 

  * x_1 < x_2 > x_3 < … < x_{2k-2} > x_{2k-1} < x_{2k}, or 
  * x_1 > x_2 < x_3 > … > x_{2k-2} < x_{2k-1} > x_{2k}. 



You need to choose a subset of distinct indices i_1, i_2, …, i_t and their order in a way that if you write down all numbers from the pairs in a single sequence (the sequence would be a_{i_1}, b_{i_1}, a_{i_2}, b_{i_2}, …, a_{i_t}, b_{i_t}), this sequence is good.

What is the largest subset of indices you can choose? You also need to construct the corresponding index sequence i_1, i_2, …, i_t.

Input

The first line contains single integer n (2 ≤ n ≤ 3 ⋅ 10^5) — the number of pairs.

Each of the next n lines contain two numbers — a_i and b_i (1 ≤ a_i, b_i ≤ 2 ⋅ n) — the elements of the pairs.

It is guaranteed that all integers in the pairs are distinct, that is, every integer from 1 to 2 ⋅ n is mentioned exactly once.

Output

In the first line print a single integer t — the number of pairs in the answer.

Then print t distinct integers i_1, i_2, …, i_t — the indexes of pairs in the corresponding order.

Examples

Input


5
1 7
6 4
2 10
9 8
3 5


Output


3
1 5 3


Input


3
5 4
3 2
6 1


Output


3
3 2 1

Note

The final sequence in the first example is 1 < 7 > 3 < 5 > 2 < 10.

The final sequence in the second example is 6 > 1 < 3 > 2 < 5 > 4.

Solution (in JAVA):

Solution:

import javax.print.attribute.IntegerSyntax;
import java.io.*;
import java.util.*;

/**
 * A simple template for competitive programming problems.
 */
public class Banana {
    final InputReader in = new InputReader(System.in);
    final PrintWriter out = new PrintWriter(System.out);

    final long mod = 1000000009;

    void solve() {
        int n = in.nextInt();
        List<Pair> firstBig = new ArrayList<>();
        List<Pair> firstSmall = new ArrayList<>();

        for(int i=0; i<n; i++) {
            int a = in.nextInt();
            int b = in.nextInt();
            if(a>b){
                firstBig.add(new Pair(a,b,i+1));
            } else {
                firstSmall.add(new Pair(a,b, i+1));
            }
        }

        if(firstBig.size()>firstSmall.size()) {
            Collections.sort(firstBig, Comparator.comparingInt(o -> o.b));
            out.println(firstBig.size());
            for(Pair p : firstBig)
                out.print(p.index + " ");
        } else {
            Collections.sort(firstSmall, Comparator.comparingInt(o -> -o.b));
            out.println(firstSmall.size());
            for(Pair p : firstSmall)
                out.print(p.index + " ");
        }
    }

    class Pair {
        int a;
        int b;
        int index;
        Pair(int a, int b, int index) {this.a = a; this.b = b; this.index = index;}

    }
    public static void main(String[] args) throws FileNotFoundException { Banana s = new Banana(); s.solve(); s.out.close(); }

    public Banana() throws FileNotFoundException { }

    private static class InputReader {
        private final InputStream stream;
        private final byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        InputReader(InputStream stream) {
            this.stream = stream;
        }

        InputReader(String fileName) {
            InputStream stream = null;
            try {
                stream = new FileInputStream(fileName);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            this.stream = stream;
        }

        int[] nextArray(int n) {
            int[] arr = new int[n];
            for (int i = 0; i < n; i++)
                arr[i] = nextInt();
            return arr;
        }

        int[][] nextMatrix(int n, int m) {
            int[][] matrix = new int[n][m];
            for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++)
                    matrix[i][j] = nextInt();
            return matrix;
        }

        String nextLine() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isEndOfLine(c));
            return res.toString();
        }

        String nextString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        long nextLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        int nextInt() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        double nextDouble() {
            return Double.parseDouble(nextString());
        }

        private int read() {
            if (numChars == -1) throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try { numChars = stream.read(buf); }
                catch (IOException e) { throw new InputMismatchException(); }
                if (numChars <= 0) return -1;
            }
            return buf[curChar++];
        }

        private boolean isSpaceChar(int c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; }

        private boolean isEndOfLine(int c) { return c == '\n' || c == '\r' || c == -1; }
    }


}