N = int(input())

def F(n):
    x = n * (n + 1) // 2
    return x * x

ans = []

import math
R_max = int((2 * (N**0.25))) * 3 + 5
R_max = max(R_max, 2)

R_max = min(R_max, 2_000_000)

for R in range(1, R_max + 1):
    FR = F(R)
    if FR < N:
        continue

    target = FR - N

    lo, hi = 0, R
    while lo <= hi:
        mid = (lo + hi) // 2
        val = F(mid)
        if val == target:
            L = mid + 1
            if L <= R:
                ans.append((L, R))
            break
        if val < target:
            lo = mid + 1
        else:
            hi = mid - 1

ans.sort()

print(len(ans))
for L, R in ans:
    print(L, R)