import sys

sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 62)

# md = 10**9+7
# md = 998244353

lim=200000

x=II()

if x==1:
    print(2)
    print(1,2)
    print("b","g")
    exit()
    
t=(x&-x).bit_length()-1
x>>=t
dd=[4]*(t>>1)+[2]*(t&1)
for d in range(3,lim+1):
    if d*d>x:break
    while x%d==0:
        dd.append(d)
        x//=d
if x>1:dd.append(x)

n=sum(dd)+len(dd)
if n>lim:
    print(-1)
else:
    print(n)
    dn=len(dd)
    for u in range(1,dn):print(u,u+1)
    s=dn+1
    for u,d in enumerate(dd,1):
        for v in range(s,s+d):print(u,v)
        s+=d
    cc=["b"]*dn+["g"]*(n-dn)
    print(*cc)