C=[0]*10
D=C[:]
for a in map(int,input().split()):C[a]+=1
for c in C:D[c]+=1
E=[i for i in range(10)if(C[i]==1and D[3]>3)|(C[i]==2and D[2]>1and D[3]>2)]
print(len(E))
print(*E)