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;
int main() {
  long long int x;
  cin >> x;
  if (x == 1) {
    cout << 1 << endl;
    cout << 1 << " " << 1;
    return 0;
  }
  vector<pair<long long int, long long int> > vt;
  long long int n = 1, m = x, pre = 0, lim = x;
  while (n < lim) {
    long long int den = n * (n + 1) / 2;
    long long int nu = (x + pre);
    long long int m = nu / den;
    lim = min(lim, m);
    if (nu % den == 0) {
      if (n != m) vt.push_back({n, m});
      vt.push_back({m, n});
    }
    pre = den + pre;
    n++;
  }
  sort(vt.begin(), vt.end());
  cout << vt.size() << '\n';
  for (int i = 0; i < vt.size(); i++)
    cout << vt[i].first << " " << vt[i].second << '\n';
  return 0;
}