N = int(input())
ans = []
for L in range(1,10**6+1):
    if L**3>N:break
    low = L
    high = 10**6+1
    while high>low+1:
        mid = (low+high)//2
        if mid*mid*(mid+1)*(mid+1)>4*N+L*L*(L-1)*(L-1):
            high = mid
        else:
            low = mid
    if low*low*(low+1)*(low+1)==4*N+L*L*(L-1)*(L-1):
        ans.append((L,low))
print(len(ans))
for L,R in ans:
    print(L,R)