#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  unsigned long long x;
  cin >> x;
  vector<pair<unsigned long long, unsigned long long> > ans;
  for (unsigned long long i = 1; i <= 3000000; i++) {
    unsigned long long hey = (x) - ((i * (i + 1) * (2 * i + 1))) / 6;
    hey -= ((i + 1) * i);
    hey += (((i + 2) * (i) * (i + 1)) / 2);
    unsigned long long foo = i * i + i - (i * (i + 1)) / 2;
    if (foo == 0) continue;
    if (hey % foo != 0) continue;
    unsigned long long res = hey / foo;
    if (res >= i) {
      ans.push_back(make_pair(i, res));
      if (res != i) ans.push_back(make_pair(res, i));
    }
  }
  sort(ans.begin(), ans.end());
  cout << ans.size() << endl;
  for (unsigned long long i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
}

### Prompt

Develop a solution in CPP to the problem described below:

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.

<image>

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>

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  unsigned long long x;
  cin >> x;
  vector<pair<unsigned long long, unsigned long long> > ans;
  for (unsigned long long i = 1; i <= 3000000; i++) {
    unsigned long long hey = (x) - ((i * (i + 1) * (2 * i + 1))) / 6;
    hey -= ((i + 1) * i);
    hey += (((i + 2) * (i) * (i + 1)) / 2);
    unsigned long long foo = i * i + i - (i * (i + 1)) / 2;
    if (foo == 0) continue;
    if (hey % foo != 0) continue;
    unsigned long long res = hey / foo;
    if (res >= i) {
      ans.push_back(make_pair(i, res));
      if (res != i) ans.push_back(make_pair(res, i));
    }
  }
  sort(ans.begin(), ans.end());
  cout << ans.size() << endl;
  for (unsigned long long i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
}

```