#39350: 集合最棒了


vincent16881688 (Strawberryyyy27)


a=list(map(int,input().split()))
b=set(a)
ans=[]
for x in b:
    ans.append(x)
    ans.sort()
    c=ans[::-1]
print(len(a)-len(ans)+1," ".join(map(str,c)))