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;
long long x;
long long k;
int broj;
int main(void) {
  cin >> x;
  k = 0;
  long long i = 1;
  for (long long i = 1; i <= sqrt(x); ++i) {
    if (k + i * i > (1000000000000000000)) goto van;
    k = k + i * i;
    if (x - k < 0) goto van;
    if ((2 * (x - k)) % (i * (i + 1)) == 0) {
      v.push_back(
          pair<long long, long long>(i, i + (2 * (x - k)) / (i * (i + 1))));
    }
  }
van:;
  for (int i = 0; i < v.size(); ++i) {
    broj++;
  }
  for (int i = v.size() - 1; i >= 0; --i) {
    if (v[i].second == v[i].first) continue;
    broj++;
  }
  cout << broj << endl;
  for (int i = 0; i < v.size(); ++i) {
    broj++;
    cout << v[i].first << " " << v[i].second << endl;
  }
  for (int i = v.size() - 1; i >= 0; --i) {
    if (v[i].second == v[i].first) continue;
    broj++;
    cout << v[i].second << " " << v[i].first << endl;
  }
  return 0;
}