from collections import defaultdict

X=int(input())
fact=defaultdict(int)
if X==1:
    print(2)
    print(1,2)
    print("b","g")
    exit()
for p in range(2,2*10**5):
    while X%p==0:
        X//=p
        fact[p]+=1
if X>1:
    fact[X]+=1
if 2 in fact:
    c=fact[2]
    fact[4]=c//2
    fact[2]=c%2
s=0
le=0
for p,e in fact.items():
    s+=(p+1)*e
    le+=e
if s>2*10**5:
    print(-1)
    exit()
ans_lst=[]
for i in range(le-1):
    ans_lst.append((i,i+1))
cur0=0
cur1=le
for p,e in fact.items():
    for i in range(e):
        for j in range(p):
            ans_lst.append((cur0,cur1))
            cur1+=1
        cur0+=1
assert len(ans_lst)==s-1
print(s)
for i,j in ans_lst:
    print(i+1,j+1)
print(*["b"]*le+["g"]*(s-le))