#include <bits/stdc++.h>
using namespace std;
const int maxn = 101010;
unsigned long long x, n, p, q;
set<pair<unsigned long long, unsigned long long> > st;
vector<pair<unsigned long long, unsigned long long> > vec;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> x;
  for (int i = 1; i <= 20 * maxn; ++i) {
    n = i;
    p = 6 * x + n * n * n - n;
    q = 3 * (n + n * n);
    if (p % q == 0 && (p / q) >= i) st.insert({i, p / q});
  }
  for (auto itr : st) {
    vec.push_back(itr);
    if (itr.first != itr.second) vec.push_back({itr.second, itr.first});
  }
  sort(vec.begin(), vec.end());
  cout << vec.size() << endl;
  for (int i = 0; i < vec.size(); ++i)
    cout << vec[i].first << " " << vec[i].second << endl;
  return 0;
}

### Prompt

Please create a solution in CPP to the following 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.

<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;
const int maxn = 101010;
unsigned long long x, n, p, q;
set<pair<unsigned long long, unsigned long long> > st;
vector<pair<unsigned long long, unsigned long long> > vec;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> x;
  for (int i = 1; i <= 20 * maxn; ++i) {
    n = i;
    p = 6 * x + n * n * n - n;
    q = 3 * (n + n * n);
    if (p % q == 0 && (p / q) >= i) st.insert({i, p / q});
  }
  for (auto itr : st) {
    vec.push_back(itr);
    if (itr.first != itr.second) vec.push_back({itr.second, itr.first});
  }
  sort(vec.begin(), vec.end());
  cout << vec.size() << endl;
  for (int i = 0; i < vec.size(); ++i)
    cout << vec[i].first << " " << vec[i].second << endl;
  return 0;
}

```