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 x;
  cin >> x;
  long long side1 = 1;
  long long s = 0;
  long long ss = 0;
  long long d = 0;
  long long c1 = 0;
  long long side2 = x;
  set<pair<long long, long long> > ans;
  for (long long side1 = 1; side1 * side1 <= x; ++side1) {
    s += c1;
    ss += s;
    c1++;
    d += c1;
    long long side2 = x + ss;
    if (side2 / d < side1) break;
    if (side2 / d >= side1 && side2 % d == 0) {
      ans.insert(make_pair(side1, side2 / d));
      ans.insert(make_pair(side2 / d, side1));
    }
  }
  printf("%d\n", (int)ans.size());
  for (set<pair<long long, long long> >::iterator it = ans.begin();
       it != ans.end(); ++it) {
    printf("%I64d %I64d\n", it->first, it->second);
  }
  return 0;
}