Problem: Spongebob is already tired trying to reason his weird actions and calculations, so he simply asked you to find all pairs of n and m, such that there are exactly x distinct squares in the table consisting of n rows and m columns. For example, in a 3 × 5 table there are 15 squares with side one, 8 squares with side two and 3 squares with side three. The total number of distinct squares in a 3 × 5 table is 15 + 8 + 3 = 26.

Input

The first line of the input contains a single integer x (1 ≤ x ≤ 1018) — the number of squares inside the tables Spongebob is interested in.

Output

First print a single integer k — the number of tables with exactly x distinct squares inside.

Then print k pairs of integers describing the tables. Print the pairs in the order of increasing n, and in case of equality — in the order of increasing m.

Examples

Input

26


Output

6
1 26
2 9
3 5
5 3
9 2
26 1


Input

2


Output

2
1 2
2 1


Input

8


Output

4
1 8
2 3
3 2
8 1

Note

In a 1 × 2 table there are 2 1 × 1 squares. So, 2 distinct squares in total.

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In a 2 × 3 table there are 6 1 × 1 squares and 2 2 × 2 squares. That is equal to 8 squares in total.

<image>

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
vector<pair<long long, long long> > v;
int main() {
  ios::sync_with_stdio(false);
  long long n;
  cin >> n;
  int idx = -1;
  n *= 2;
  for (int i = 1;; i++) {
    long long x = 1ll * i * (i + 1) * (2 * i + 1);
    x /= 6;
    long long k = n / 2 - x;
    long long y = 1ll * i * (i + 1);
    y /= 2;
    if (k < 0) break;
    if (k % y != 0) continue;
    x = k / y + i;
    idx = i;
    v.push_back(make_pair(i, x));
    if (i != x) v.push_back(make_pair(x, i));
  }
  sort(v.begin(), v.end());
  cout << v.size() << endl;
  for (int i = 0; i < v.size(); i++)
    cout << v[i].first << " " << v[i].second << endl;
}