from collections import *
def prime_decomposition(N): #O(sqrt(N))
    P=defaultdict(int)
    for i in range(2,N):
        if i*i>N:
            break
        if i>2*10**5:
            print(-1)
            exit()
        if N%i==0:
            j=0
            while N%i==0:
                N//=i
                j+=1
            P[i]=j
    if N!=1:
        P[N]=1
    return P

X=int(input())
if X==1:
    print(2)
    print(1,2)
    print('b','g')
    exit()
px=prime_decomposition(X)

L=[]
for k,v in px.items():
    if k==2:
        for _ in range(v//2):
            L.append(4)
        if v%2==1:
            L.append(2)
    else:
        for _ in range(v):
            L.append(k)

s=0
for i in L:
    s+=i+1

if s>2*10**5:
    print(-1)
    exit()

print(s)
for i in range(len(L)-1):
    print(i+1,i+2)

now=len(L)
for i in range(len(L)):
    for _ in range(L[i]):
        print(i+1,now+1)
        now+=1

C=[None]*now
for i in range(len(L)):
    C[i]='b'
for i in range(len(L),now):
    C[i]='g'

print(*C)