import sys
input = sys.stdin.readline

from random import randint

N,X,Y=map(int,input().split())

if X==Y:
    print(0)
    exit()

if Y%2==0:
    print(-1)
    exit()

def f(i,x):
    return (x*(1<<i) + 1)%(1<<N)

#print()

#for X in range(1,2**N):
#    now=X
#    for i in range(1,N+1):
#        to=f(i,now)
#        print(to,end=" ")
#    print()

ANS=[N]

LIST=[Y]

while LIST[-1]!=1:
    x=LIST[-1]-1
    while x%2==0:
        x//=2
    LIST.append(x)

LIST.reverse()

for i in range(len(LIST)-1):
    ind=-1
    for j in range(1,N+1):
        if LIST[i+1]==f(j,LIST[i]):
            ind=j
            break
    ANS.append(ind)

print(len(ANS))
print(*ANS)