
# 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 = list(map(int, input().split()))

cnt = 0



for i in range(a, b+1):

    i = str(i)

    if i[0] == i[-1] and i[1] == i[-2]:

        cnt += 1



print(cnt)


# optimized version of the same code:

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

cnt = 0



for i in range(10):

    for j in range(10):

        for k in range(10):

            c = 10000*i+1000*j+100*k+10*j+i

            if a <= c <= b:

                cnt += 1



print(cnt)

a, b = list(map(int, input().split()))
cnt = 0
for i in range(a, b + 1):
    i = str(i)
    if i[0] == i[-1] and i[1] == i[-2]:
        cnt += 1
print(cnt)

a, b = list(map(int, input().split()))
cnt = 0
for i in range(10):
    for j in range(10):
        for k in range(10):
            c = 10000 * i + 1000 * j + 100 * k + 10 * j + i
            if a <= c <= b:
                cnt += 1
print(cnt)

-for i in range(a, b + 1): -    i = str(i) -    if i[0] == i[-1] and i[1] == i[-2]: -        cnt += 1 +for i in range(10): +    for j in range(10): +        for k in range(10): +            c = 10000 * i + 1000 * j + 100 * k + 10 * j + i +            if a <= c <= b: +                cnt += 1