
# 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:

S, T = [list(eval(input())) for _ in range(2)]

cnt = 0

for i in range(len(S)):

    if S[i] != T[i]:

        cnt += 1

print(cnt)


# optimized version of the same code:

s, t = [eval(input()) for i in range(2)]

ans = 0

for i in range(len(s)):

  if s[i] != t[i]:

    ans += 1

print(ans)
S, T = [list(eval(input())) for _ in range(2)]
cnt = 0
for i in range(len(S)):
    if S[i] != T[i]:
        cnt += 1
print(cnt)

s, t = [eval(input()) for i in range(2)]
ans = 0
for i in range(len(s)):
    if s[i] != t[i]:
        ans += 1
print(ans)

-S, T = [list(eval(input())) for _ in range(2)] -cnt = 0 -for i in range(len(S)): -    if S[i] != T[i]: -        cnt += 1 -print(cnt) +s, t = [eval(input()) for i in range(2)] +ans = 0 +for i in range(len(s)): +    if s[i] != t[i]: +        ans += 1 +print(ans)