A,B=map(int,input().split())

A0=0
A1=0

for i in range(32):
    if A & (1<<i)==0 and B & (1<<i)!=0:
        A0+=1
    elif A & (1<<i)!=0 and B & (1<<i)==0:
        A1+=1
if A0 and A1:
    print(0)
elif A0==A1==0:
    print(1)
else:    
    N=50
    Combi=[[] for i in range(N+1)]
    Combi[0]=[1,0]

    for i in range(1,N+1):
        Combi[i].append(1)
        for j in range(i):
            Combi[i].append(Combi[i-1][j]+Combi[i-1][j+1])
        Combi[i].append(0)

    A=max(A0,A1)
    ANS=0

    for j in range(A+1):
        ANS+=Combi[A][j]

    print(ANS//2)