inf = 1<<60
X = int(input())
if X == 1:
    print(2)
    print(1, 2)
    exit(print('b', 'g'))

limit = 2*10**5
def prime_factorize(n):
    a = []
    while n % 4 == 0:
        a.append(4)
        n //= 4
    if n % 2 == 0:
        a.append(2)
        n //= 2
    f = 3
    while f * f <= n:
        # limit を超えるような素因数は不適格
        if f >= limit:
            return [inf]

        if n % f == 0:
            a.append(f)
            n //= f
        else:
            f += 2
    if n != 1:
        a.append(n)
    return a

prime_factors = prime_factorize(X)

# 茶色から採番
N = len(prime_factors) # 1 ~ N

# 緑色の個数
M = sum(prime_factors)

# 全部の頂点数
V = N + M

if V > limit:
    exit(print(-1))

print(V)
# 茶色同士を連結するedge
# 1 と 2
# ...
# N - 1 と N
for i in range(1, N):
    print(i, i + 1)

# 各茶色頂点i と緑頂点を連結するedge
cnt = N + 1 # から採番
for i in range(1, N + 1):
    # メンバー数は prime_factors[i - 1]
    for j in range(prime_factors[i - 1]):
        print(i, cnt)
        cnt += 1

color = ['b'] * N + ['g'] * M
print(*color)