
# 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:

a, b, c = sorted(map(int, input().split()))



print((c*10 + b + a))

# optimized version of the same code:

a, b, c = list(map(int, input().split()))



print((max(a, b, c)*9 + (a + b + c)))
a, b, c = sorted(map(int, input().split()))
print((c * 10 + b + a))

a, b, c = list(map(int, input().split()))
print((max(a, b, c) * 9 + (a + b + c)))

-a, b, c = sorted(map(int, input().split())) -print((c * 10 + b + a)) +a, b, c = list(map(int, input().split())) +print((max(a, b, c) * 9 + (a + b + c)))