INFTY = 2*10**5
P = list(range(INFTY+1))
P[1] = 0
for i in range(2,INFTY+1):
    if i*i>INFTY:break
    for j in range(i*i,INFTY+1,i):
        P[j] = P[i]
Q = []
for i in range(2,INFTY+1):
    if P[i] == i:
        Q.append(i)
X = int(input())
if X==1:
    print(2)
    print(1,2)
    print("b","g")
else:
    D = {}
    x = X
    for p in Q:
        if x==1:break
        while x%p==0:
            D[p] = D.get(p,0)+1
            x = x//p
    if x>1:
        print(-1)
    else:
        A = []
        Col = {}
        v = 1
        V = []
        for p in D:
            if p==2:
                for i in range(D[p]//2):
                    if len(V)>0:
                        A.append((V[-1],v))
                    for j in range(1,4+1):
                        A.append((v,v+j))
                        Col[v+j] = "g"
                    V.append(v)
                    Col[v] = "b"
                    v += 5
                if D[p]%2==1:
                    if len(V)>0:
                        A.append((V[-1],v))
                    for j in range(1,2+1):
                        A.append((v,v+j))
                        Col[v+j] = "g"
                    V.append(v)
                    Col[v] = "b"
                    v += 3
            else:
                for i in range(D[p]):
                    if len(V)>0:
                        A.append((V[-1],v))
                    for j in range(1,p+1):
                        A.append((v,v+j))
                        Col[v+j] = "g"
                    V.append(v)
                    Col[v] = "b"
                    v += p+1
        n = len(A)+1
        if n>INFTY:
            print(-1)
        else:
            print(n)
            for u,v in A:
                print(u,v)
            Col = sorted(list(Col.items()),key=lambda x:x[0])
            Col = [Col[i][1] for i in range(n)]
            print(*Col)