X = int(input())
prime = list()

while True:
    ok = False
    for i in range(2, 2*10**5+1):
        if X%i==0:
            ok = True
            X //= i
            prime.append(i)
            break
    if not ok:
        break
if X!=1:
    prime.append(X)
#print(prime)
if X>2*10**5 or 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, 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)