import sys
# import sympy


def debug(*args):
    print(*args, file=sys.stderr)


x = int(input())
if x == 1:
    print(2)
    print(1, 2)
    print('b', 'g')
    exit()


def sieve_of_eratosthenes(limit):
    sieve = [True] * (limit + 1)
    sieve[0] = sieve[1] = False
    for start in range(2, int(limit**0.5) + 1):
        if sieve[start]:
            for i in range(start * start, limit + 1, start):
                sieve[i] = False
    return [num for num, is_prime in enumerate(sieve) if is_prime]


primes = sieve_of_eratosthenes(2 * (10**5))
primes[0] = 4
primes.append(2)


parent = 1
edges = []
c = ['b']
for p in primes:
    while x % p == 0:
        x //= p
        for i in range(parent+1, parent+p+1):
            edges.append([parent, i])
            c.append('g')
        edges.append([parent, parent+p+1])
        c.append('b')
        parent = len(c)
        if len(c) > 2*(10**5):
            print(-1)
            exit()
    if x == 1:
        print(len(c)-1)
        for u, v in edges[:-1]:
            print(u, v)
        print(*c[:-1])
        exit()
    elif len(c) > 2*(10**5):
        print(-1)
        exit()

print(-1)