x=int(input())

# 素因数分解
import math 
L=int(math.sqrt(x))

FACT=dict()

for i in range(2,L+2):
    while x%i==0:
        FACT[i]=FACT.get(i,0)+1
        x=x//i

if x!=1:
    FACT[x]=FACT.get(x,0)+1

LIST=[]

for f in FACT:
    x=FACT[f]

    if f==2:
        while x>=2:
            LIST.append(4)
            x-=2

        if x==1:
            LIST.append(2)
    else:
        for i in range(x):
            LIST.append(f)

if len(LIST)+sum(LIST)>200000:
    print(-1)
else:
    X=len(LIST)+sum(LIST)
    print(X)

    ANS=[]
    for i in range(1,len(LIST)):
        ANS.append((i,i+1))

    c=len(LIST)+1

    for i in range(1,len(LIST)+1):
        for j in range(LIST[i-1]):
            ANS.append((i,c))
            c+=1

    for x,y in ANS:
        print(x,y)

    LL=["b"]*len(LIST)+["g"]*sum(LIST)

    print(" ".join(LL))