def factorization(n):
    arr = []
    temp = n
    for i in range(2, int(n**(1/2)+5)):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr.append([i, cnt])

    if temp!=1:
        arr.append([temp, 1])

    if arr==[]:
        arr.append([n, 1])

    return arr

n = int(input())
F = factorization(n)
A = []

for i in range(len(F)):
    if(F[i][0] == 2):
        for _ in range(F[i][1] // 2):
            A.append(4)
            
        for _ in range(F[i][1] % 2):
            A.append(2)
    else:
        for _ in range(F[i][1]):
            A.append(F[i][0])

cnt = len(A) + sum(A)

bl = False
for i in range(2,2*10**5+1):
    if(n%i == 0):
        bl = True
        
if(cnt > 2*10**5 or bl==False):
    print(-1)
    exit()
    
E = []
C = [-1] * cnt

v = 0
for i in range(len(A)):
    u = v
    C[u] = "b"
    for _ in range(A[i]):
        v += 1
        E.append([u+1, v+1])
        C[v] = "g"
    v += 1

print(cnt)
for e in E:
    print(*e)
print(*C)