#include <bits/stdc++.h>
using namespace std;
long long sq(long long m) { return (m * (m + 1) * (2 * m + 1)) / 6; }
long long fff(long long m) { return (m * (m + 1)) / 2; }
int main() {
  long long x;
  cin >> x;
  long long n;
  vector<pair<long long, long long> > ans, rev;
  for (n = 1; n <= 1442255; n++) {
    long long fir = sq(n);
    if (fir > x) break;
    fir = x - fir;
    long long y = fff(n);
    if (fir % y == 0) {
      y = fir / y;
      ans.push_back(make_pair(n, n + y));
      if (y != 0) rev.push_back(make_pair(n + y, n));
    }
  }
  printf("%d\n", ans.size() + rev.size());
  reverse(rev.begin(), rev.end());
  int i;
  for (i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
  ans = rev;
  for (i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
  return 0;
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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;
long long sq(long long m) { return (m * (m + 1) * (2 * m + 1)) / 6; }
long long fff(long long m) { return (m * (m + 1)) / 2; }
int main() {
  long long x;
  cin >> x;
  long long n;
  vector<pair<long long, long long> > ans, rev;
  for (n = 1; n <= 1442255; n++) {
    long long fir = sq(n);
    if (fir > x) break;
    fir = x - fir;
    long long y = fff(n);
    if (fir % y == 0) {
      y = fir / y;
      ans.push_back(make_pair(n, n + y));
      if (y != 0) rev.push_back(make_pair(n + y, n));
    }
  }
  printf("%d\n", ans.size() + rev.size());
  reverse(rev.begin(), rev.end());
  int i;
  for (i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
  ans = rev;
  for (i = 0; i < ans.size(); i++)
    cout << ans[i].first << " " << ans[i].second << endl;
  return 0;
}

```