
# slower version:

s = input()
for i in range(len(s)):
  if i%2 == 0:
    print(s[i], end = '')


# optimized version of the same code:

s = input()
ans = ''
for i in range(len(s)):
  if i % 2 == 0:
    ans += s[i]
print(ans)



# slower version:

print((sum(si != ti for si, ti in zip(eval(input()), eval(input())))))


# optimized version of the same code:

print((sum(a!=b for a,b in zip(*open(0)))))
print((sum(si != ti for si, ti in zip(eval(input()), eval(input())))))

print((sum(a != b for a, b in zip(*open(0)))))

-print((sum(si != ti for si, ti in zip(eval(input()), eval(input()))))) +print((sum(a != b for a, b in zip(*open(0)))))