def factorization(n):
    arr = []
    temp = n
    for i in range(2, int(-(-n**0.5//1))+1):
        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)
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

if(n > 2**10**5):
    print(-1)
    
print(n)
for e in E:
    print(*e)
print(*C)