bcdef
abbbc
 z
y
 reddit
abcdef
 abc
aaa
 y
z
 cbxz
aaaa

bccdb
 z
 dfdeed
 aab
 y
 abac

s = sorted(list(input()))
t = sorted(list(input()))
l=0
while l<len(t):
    print(s.pop(0),end="")
    l+=1
    if l<len(t):
        
        print(t.pop(),end="")
        