s = eval(input())

print((s[0:len(s)+1:2]))
s = str(eval(input()))

 

print((s[::2]))
s = eval(input())
print((s[0 : len(s) + 1 : 2]))

s = str(eval(input()))
print((s[::2]))

-s = eval(input()) -print((s[0 : len(s) + 1 : 2])) +s = str(eval(input())) +print((s[::2]))