def prime_numbers(m):
    primes = set()
    n = 2
    while n<=m:
        if all(n % i != 0 for i in primes):
            primes.add(n)
        n += 1
    return primes

X = int(input())
tmp_prime = list()
if X!=1:
    primes = prime_numbers(2*10**5)
    while True:
        ok = False
        for i in primes:
            if X%i==0:
                ok = True
                X //= i
                tmp_prime.append(i)
                break
        if not ok:
            break
    #print(tmp_prime)
    prime = list()
    cnt_2 = 0
    for i in tmp_prime:
        if i==2:
            if cnt_2==1:
                prime.append(4)
                cnt_2 = 0
            else:
                cnt_2 += 1
        else:
            if cnt_2==2:
                prime.append(4)
                cnt_2 = 0
            elif cnt_2==1:
                prime.append(2)
                cnt_2 = 0
            prime.append(i)
    if X!=1:
        prime.append(X)
    #print(prime)
    #print("#", len(prime), sum(prime))
else:
    prime = [1]
if X>2*10**5 or len(prime)+sum(prime)>2*10**5:
    print(-1)
    exit()
N = len(prime)+sum(prime)
G = [ [] for _ in range(N+1)]
idx = len(prime)
for i in range(1, len(prime)+1):
    for j in range(prime[i-1]):
        idx += 1
        G[i].append(idx)
print(N)
for i in range(1, len(prime)):
    G[i].append(i+1)
for i in range(1, N+1):
    for j in G[i]:
        print(i,j)
col = list()
for i in range(len(prime)):
    col.append("b")
for i in range(sum(prime)):
    col.append("g")
print(*col)