# ABC073b

import sys

input = sys.stdin.readline

sys.setrecursionlimit(10**6)



s = input()



for i in range(0, len(s), 2):

    print(s[i], end='')

# ABC073b

import sys

input = sys.stdin.readline

sys.setrecursionlimit(10**6)



s = eval(input())

ans = ''



for i in range(0, len(s), 2):

    ans += s[i]

print(ans)
# ABC073b
import sys

input = sys.stdin.readline
sys.setrecursionlimit(10**6)
s = input()
for i in range(0, len(s), 2):
    print(s[i], end="")

# ABC073b
import sys

input = sys.stdin.readline
sys.setrecursionlimit(10**6)
s = eval(input())
ans = ""
for i in range(0, len(s), 2):
    ans += s[i]
print(ans)

-s = input() +s = eval(input()) +ans = "" -    print(s[i], end="") +    ans += s[i] +print(ans)