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 CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
const int N = 100005, M = 1000000007;
int n, i, a, b, n1, n2;
struct str {
  int a, b, t;
} s1[300005], s2[300005];
bool cmp1(str a, str b) { return a.a > b.a; }
bool cmp2(str a, str b) { return a.a < b.a; }
int main() {
  scanf("%d", &n);
  for (i = 1; i <= n; i++) {
    scanf("%d %d", &a, &b);
    if (a < b)
      s1[++n1] = (str){a, b, i};
    else
      s2[++n2] = (str){a, b, i};
  }
  if (n1 > n2) {
    sort(s1 + 1, s1 + 1 + n1, cmp1);
    printf("%d\n", n1);
    for (i = 1; i <= n1; i++) printf("%d ", s1[i].t);
  } else {
    sort(s2 + 1, s2 + 1 + n2, cmp2);
    printf("%d\n", n2);
    for (i = 1; i <= n2; i++) printf("%d ", s2[i].t);
  }
}