N=int(input())

if N==1:
  print(2)
  print(1,2)
  print('b','g') 
  exit()
  
if N==2:
  print(3)
  print(1,3)
  print(2,3)
  print('g','g','b')
  exit()

A=[]
for i in range(3,2*10**5+1):
  while N%i==0:
    A.append(i)
    N//=i 


if N!=1:
  A.append(N)

if sum(A)+len(A)>2*10**5:
  print(-1)
  exit()
  
l=sum(A)+len(A)
ans=['g']*l
for i in range(len(A)):
  ans[i]='b'
  
B=[];now=len(A)
for i in range(len(A)):
  if i!=0:
    B.append((i,i+1))
  for j in range(A[i]):
    now+=1
    B.append((i+1,now))

print(len(B)+1)
for x,y in B:
  print(x,y)
print(*ans)