a=list(map(int,input().split(",")))
b=list(map(int,input().split(",")))
la=len(a);lb=len(b)    
ia,ib=0,0;c=[]
while __________:
    if a[ia]<b[ib]:
        k=a[ia]
        ia+=1
    else:
        if a[ia]==b[ib]:
            __________
        k=b[ib]
        ib+=1
    __________
c+=a[ia:]
c+=b[ib:]
for i in c:
    print(i,end=" ")