桶排

a=input().split()
b=input().split()
c=max(a[-1],b[-1])
d=[0]*(int(c)+1)
for i in range(len(a)):
    i=a[i]
    d[int(i)]+=1
for i in range(len(b)):
    i=b[i]
    d[int(i)]+=1
for i in range(len(d)):
    while d[i]!=0:
        print(i,end=" ")
        d[i]-=1