
# 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:

N,Ma,Mb = list(map(int, input().split()))

arr=[list(map(int,input().split())) for _ in range(N)]

dp=[[[5000]*401 for _ in range(401)] for _ in range(41)]

dp[0][0][0] = 0

for i in range(N):

    a,b,c=arr[i]

    for j in range(10*N+1):

        for k in range(10*N+1):

            if dp[i][j][k] == 5000:

                continue

            dp[i+1][j][k]=min(dp[i+1][j][k],dp[i][j][k])

            dp[i+1][j+a][k+b]=min(dp[i+1][j+a][k+b],dp[i][j][k]+c)



ans=5000

for i in range(1,401):

        if i*Ma>400 or i*Mb>400:

            break

        ans = min(ans, dp[N][i*Ma][i*Mb])

if ans == 5000:

    print((-1))

else:

    print(ans)

# optimized version of the same code:

def calc():

    N,Ma,Mb = list(map(int, input().split()))

    arr=[list(map(int,input().split())) for _ in range(N)]

    dp=[[[5000]*401 for _ in range(401)] for _ in range(41)]

    dp[0][0][0] = 0

    for i in range(N):

        a,b,c=arr[i]

        for j in range(10*N+1):

            for k in range(10*N+1):

                if dp[i][j][k] == 5000:

                    continue

                dp[i+1][j][k]=min(dp[i+1][j][k],dp[i][j][k])

                dp[i+1][j+a][k+b]=min(dp[i+1][j+a][k+b],dp[i][j][k]+c)



    ans=5000

    for i in range(1,401):

            if i*Ma>400 or i*Mb>400:

                break

            ans = min(ans, dp[N][i*Ma][i*Mb])

    if ans == 5000:

        print((-1))

    else:

        print(ans)



calc()
N, Ma, Mb = list(map(int, input().split()))
arr = [list(map(int, input().split())) for _ in range(N)]
dp = [[[5000] * 401 for _ in range(401)] for _ in range(41)]
dp[0][0][0] = 0
for i in range(N):
    a, b, c = arr[i]
    for j in range(10 * N + 1):
        for k in range(10 * N + 1):
            if dp[i][j][k] == 5000:
                continue
            dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k])
            dp[i + 1][j + a][k + b] = min(dp[i + 1][j + a][k + b], dp[i][j][k] + c)
ans = 5000
for i in range(1, 401):
    if i * Ma > 400 or i * Mb > 400:
        break
    ans = min(ans, dp[N][i * Ma][i * Mb])
if ans == 5000:
    print((-1))
else:
    print(ans)

def calc():
    N, Ma, Mb = list(map(int, input().split()))
    arr = [list(map(int, input().split())) for _ in range(N)]
    dp = [[[5000] * 401 for _ in range(401)] for _ in range(41)]
    dp[0][0][0] = 0
    for i in range(N):
        a, b, c = arr[i]
        for j in range(10 * N + 1):
            for k in range(10 * N + 1):
                if dp[i][j][k] == 5000:
                    continue
                dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k])
                dp[i + 1][j + a][k + b] = min(dp[i + 1][j + a][k + b], dp[i][j][k] + c)
    ans = 5000
    for i in range(1, 401):
        if i * Ma > 400 or i * Mb > 400:
            break
        ans = min(ans, dp[N][i * Ma][i * Mb])
    if ans == 5000:
        print((-1))
    else:
        print(ans)


calc()

-N, Ma, Mb = list(map(int, input().split())) -arr = [list(map(int, input().split())) for _ in range(N)] -dp = [[[5000] * 401 for _ in range(401)] for _ in range(41)] -dp[0][0][0] = 0 -for i in range(N): -    a, b, c = arr[i] -    for j in range(10 * N + 1): -        for k in range(10 * N + 1): -            if dp[i][j][k] == 5000: -                continue -            dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k]) -            dp[i + 1][j + a][k + b] = min(dp[i + 1][j + a][k + b], dp[i][j][k] + c) -ans = 5000 -for i in range(1, 401): -    if i * Ma > 400 or i * Mb > 400: -        break -    ans = min(ans, dp[N][i * Ma][i * Mb]) -if ans == 5000: -    print((-1)) -else: -    print(ans) +def calc(): +    N, Ma, Mb = list(map(int, input().split())) +    arr = [list(map(int, input().split())) for _ in range(N)] +    dp = [[[5000] * 401 for _ in range(401)] for _ in range(41)] +    dp[0][0][0] = 0 +    for i in range(N): +        a, b, c = arr[i] +        for j in range(10 * N + 1): +            for k in range(10 * N + 1): +                if dp[i][j][k] == 5000: +                    continue +                dp[i + 1][j][k] = min(dp[i + 1][j][k], dp[i][j][k]) +                dp[i + 1][j + a][k + b] = min(dp[i + 1][j + a][k + b], dp[i][j][k] + c) +    ans = 5000 +    for i in range(1, 401): +        if i * Ma > 400 or i * Mb > 400: +            break +        ans = min(ans, dp[N][i * Ma][i * Mb]) +    if ans == 5000: +        print((-1)) +    else: +        print(ans) + + +calc()