Problem:
 Score : 200 points    Problem Statement You are given a string s consisting of lowercase English letters. Extract all the characters in the odd-indexed positions and print the string obtained by concatenating them. Here, the leftmost character is assigned the index 1 .      Constraints  Each character in s is a lowercase English letter.  1≤|s|≤10^5         Input The input is given from Standard Input in the following format:  s       Output Print the string obtained by concatenating all the characters in the odd-numbered positions.        Sample Input 1 atcoder      Sample Output 1 acdr  Extract the first character a , the third character c , the fifth character d and the seventh character r to obtain acdr .       Sample Input 2 aaaa      Sample Output 2 aa       Sample Input 3 z      Sample Output 3 z       Sample Input 4 fukuokayamaguchi      Sample Output 4 fkoaaauh

Solution (Python):
s = input()

ss = ""
for i in range(len(s)):
    if (i + 1) % 2 == 1:
        ss += s[i]

print(ss)

Solution (Python):
s=input()
a = []
for i in range(0,len(s),2):
    a.append(s[i])
print("".join(a))

Solution (Python):
s = input()
s_add = ""
for i in range(len(s)):
  if i % 2 == 0:
    s_add = s_add + s[i]
print(s_add)

Solution (Python):
x = input()
print(x[::2])

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
s = input()
for i in range(len(s)):
    if i % 2 == 0:
        print(s[i], end="")
print()

Solution (Python):
str = input()
print(str[::2])

Solution (Python):
s = input()
t = ""
for i in range(len(s)):
    if i % 2 == 0:
        t += s[i]
print(t)

Solution (Python):
S=list(input())

Ts=""
for i in range(len(S)):
    if i%2==0:
        Ts+=S[i]

print(Ts)

Solution (Python):
s = input()
ans = '' 
for i in range(len(s)):
    if i % 2 == 0:
        ans += s[i]

print(ans)

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[0::2])

Solution (Python):
s = list(input())
print(''.join(s[0::2]))

Solution (Python):
s=input()
for i,c in enumerate(s):
    if i%2==0: print(c,end="")
print()

Solution (Python):
s = input()
print(''.join([s[i] for i in range(len(s)) if i%2 == 0]))

Solution (Python):
import numpy as np
import pdb

def main():
    mystring = np.array(list(raw_input()))
    oddstr = oddstring(mystring)
    oddstr = ''.join(oddstr)
    print oddstr

def oddstring(mystring):
    stringsize = len(mystring)
    oddindices = range(0,stringsize, 2)
    oddstr = mystring[oddindices]
    return oddstr

if __name__ == '__main__':
    main()

Solution (Python):




print(input()[::2])

Solution (Python):
s=input()

l=[]
for i in range(len(s)):
    if(i%2==0):
        l.append(s[i])
ss="".join(l)
print(ss)

Solution (Python):
s=list(input())
ans=""
for i in range(0,len(s),2):
    ans+=s[i]
print(ans)

Solution (Python):
a=input().strip()
b=''
for i in range(0,len(a),2):
  b=b+a[i]
print(b)

Solution (Python):
s=input()
print(''.join([c for i,c in enumerate(s) if i%2==0]))

Solution (Python):
print(input()[0::2])

Solution (Python):
print(input()[::2])

Solution (Python):
s=input()
b=len(s)

c=0

for i in range(b):
    if i%2==0:
        c=str(c)+str(s[i])

print(c[1:])

Solution (Python):
s = input()

print(s[::2])

Solution (Python):


s = input()
sList = list(s)

output = ""

for i in range(len(sList)):
    if i%2 == 0:
        output += sList[i]

print(output)

Solution (Python):
s=input();s_list=list(s);ans=''
for i in range(1,int(len(s_list)/2)+1):
    del s_list[i]
for i in s_list:
    ans += i
print(ans)

Solution (Python):


s = input()
for i in range(len(s)):
    if i % 2 == 0:
        print(s[i], end="")
print()

Solution (Python):
a = input()
p = str()
for i in range(len(a)):
    if i % 2 == 0:
        p += a[i]
print(p)

Solution (Python):
print(input()[::2])

Solution (Python):
s = input()
a =''
for i in range(len(s)):
	if i % 2 == 0:
		a += s[i]
		
print(a)

Solution (Python):
s = input()
s_list = list(s)

ans = [j for i,j in enumerate(s_list) if (i%2) == 0]
print(''.join(ans))

Solution (Python):
s = input()
a = ""
for i in range(len(s)):
    if(i % 2 == 0):
        a += s[i]
print(a)

Solution (Python):
s = raw_input()
print s[::2]

Solution (Python):
s = input()

print(s[::2])

Solution (Python):
s = input()
print("".join([s[i] for i in range(0, len(s), 2)]))

Solution (Python):
value = input()

array = []
for i in range(0, len(value)):
    if i%2 == 0:
        array.append(value[i])
print("".join(array))

Solution (Python):
x = ""
s = input()
for i in range(len(s)):
 if i % 2 == 0:
  x = x + s[i]
print(x)

Solution (Python):
s=input()
i=0
a=""
while i<len(s):
 a+=s[i]
 i+=2
print(a)

Solution (Python):
print(input()[0::2])

Solution (Python):
s = input()
s2 = ''
for i in range(len(s)):
    if (i % 2 == 0):
        s2 += s[i]

print(s2)

Solution (Python):
s = list(input())
n = len(s)
ans = ""
for i in range(0, n, 2):
    ans += s[i]
print(ans)

Solution (Python):
s = raw_input()
print "".join(s[i] for i in xrange(len(s)) if i%2 == 0)

Solution (Python):
s = raw_input("")
print s[::2]

Solution (Python):





def main():
    S = input()
    print(S[::2])

if __name__ == "__main__": main()

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
def B_OddString():
    try:
        LOCAL_FLAG
        s = "a"
    except NameError:
        s = input()

    for i in range(0,len(s),2):
        print(s[i], end='')


B_OddString()

Solution (Python):
print(str(input())[::2])

Solution (Python):
s = input()
ans = ''
count = 0
while True:
    ans += s[count]
    count += 1
    if len(s) == count:
        break
    count += 1
    if len(s) == count:
        break

print(ans)

Solution (Python):
n = list(input())
for i in range(len(n)):
    if i%2 == 0: print(n[i],end="")
print()

Solution (Python):
s=str(input())
L=len(s)
ans=''
for i in range(0,L,2):
    ans += s[i]

print(ans)

Solution (Python):
st=input()
s=""
for i in range(0,len(st)):
    if i % 2 ==0:
        s+=str(st[i])
    else:
        pass
print(s)

Solution (Python):
def main():
    print(''.join([c for c in input()[::2]]))


if __name__ == "__main__":
    main()

Solution (Python):
s = input()

for i , t in enumerate(s):
  if i%2 == 0:
    print(t,end = "")
print()

Solution (Python):
print(input()[::2])

Solution (Python):
s = input()
for i in range(0, len(s), 2):
    print(s[i], end='')
print()

Solution (Python):
string = input()
answer = [character for i, character in enumerate(string) if i%2 == 0]
for character in answer:
    print(character, end="", sep="")

Solution (Python):
if __name__ == '__main__':
    S = input()
    ans = ""
    n = len(S) - int(len(S)/2)
    for i in range(n):
        ans += S[2*i]
    print(ans)

Solution (Python):
s = input()
for i in range((len(s)+1)//2):
  print(s[2*i], end="")
print("")

Solution (Python):
s = raw_input()
print s[::2]

Solution (Python):
string = input()
size = len(string)
out = ""
for i in range(size):
    if i % 2 == 0:
        out += string[i]
print(out)

Solution (Python):
print(input()[::2])

Solution (Python):
a=raw_input()
t=''
for i in range(0,len(a)):
 t+="" if i%2 else a[i]
print t

Solution (Python):
S = input()
t = ""
for i in range(0, len(S), 2):
  t = t + S[i]

print(t)

Solution (Python):
print(input()[::2])

Solution (Python):
s = input()
for i in range(0, len(s), 2):
    print(s[i], end='')
print()

Solution (Python):
s = list(input())


for i in range(len(s)):
    if i%2==0:
        print(s[i],end='')

print()

Solution (Python):
print(input()[::2])

Solution (Python):
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**10
mod = 10**9+7

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()


def main():
    s = S()

    return s[::2]


print(main())

Solution (Python):
s = input()
ans = ""
n = len(s)
for i in range(len(s)):
    if i % 2 == 0:
        ans = ans + s[i]
print(ans)

Solution (Python):
s = input()
t = [s[i] for i in range(0, len(s), 2)]
print(''.join(t))

Solution (Python):
def main():
    S =  input()
    
    
    
    
    string = "".join( [S[i] for i in range(0, len(S), 2)] )
    print(string)
    
    
if __name__=="__main__":
    main()

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
from collections import defaultdict
from itertools import product, groupby
from math import pi
from collections import deque
from bisect import bisect, bisect_left, bisect_right
INF = 10 ** 10


def main():
    s = input()
    print(s[::2])


if __name__ == '__main__':
    main()

Solution (Python):
s = input()

print(s[::2])

Solution (Python):

s = input().rstrip()

print(s[::2])

Solution (Python):
s = input() 
print(s[::2])

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
S=input()
print(S[::2])

Solution (Python):
s = input()
for i in range(len(s)):
    if (i % 2) == 0:
        print(s[i], end="")
print()

Solution (Python):
s = input()
ans = ""
for i in range(0,len(s),2):
    ans += s[i]
print(ans)

Solution (Python):
def main():
    print(input()[::2])

if __name__ == '__main__':
    main()

Solution (Python):


str =""
i =1
for j in input():
    if i%2==1:
        str+=j
    i+=1
print(str)

Solution (Python):
print(input()[::2])

Solution (Python):
def oddOut():
    s = str(input())
    print(s[::2])
oddOut()

Solution (Python):
print(input()[::2])

Solution (Python):

str = input()

kisuu_str = ""
for i in range(0,len(str),2):
    kisuu_str += str[i]

print(kisuu_str)

Solution (Python):
print(input()[::2])

Solution (Python):
s = input()
t = len(s)
for i in range(0,t,2) :
    print (s[i] , end='')

Solution (Python):
s = input()
t = len(s)
for i in range(0,t,2) :
    print (s[i] , end='')
    
print()

Solution (Python):
s = input()
ans = ""
for i in range(0, len(s), 2):
    ans += s[i]
print(ans)

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
s = str(raw_input())
lst = []
for i in range(len(s)):
    if i % 2 == 0:
        lst.append(s[i])
print ''.join(lst)

Solution (Python):
print(input()[::2])

Solution (Python):
S = input()
t = 0
i = 0
A=[]

while t< len(S):
    A.append(S[t])
    i+=1
    t+=2
a="".join(A)
print(a)

Solution (Python):
print raw_input()[::2]

Solution (Python):

s = list(input())
a = [ s[tmp] for tmp in range(len(s)) if tmp%2 == 0 ]
print(''.join(a))

Solution (Python):
s = str(input())
print(s[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
s = input()
ans = s[0:100000:2]
print(ans)

Solution (Python):
s=input()
x=list(s)
out=""
for i in range(len(x)):
	if i % 2 ==0:
		out+=x[i]
print(out)

Solution (Python):
print(input()[0::2])

Solution (Python):
print(input()[::2])

Solution (Python):
print("".join(list(input())[::2]))

Solution (Python):
s=input()
print(s[0:len(s):2])

Solution (Python):
print "".join([c for i,c in enumerate(raw_input()) if i % 2 == 0])

Solution (Python):
print "".join(map(str, [c for i,c in enumerate(raw_input()) if i % 2 == 0]))

Solution (Python):
import sys

word = raw_input()
odd = ''
index = 1

for letter in word:
    if (index % 2) != 0:
        odd += letter
    index += 1

print odd

Solution (Python):
input_line1 = str(input())
c = 1
p = ""
for v in input_line1:
    if c == 1:
        p += v
        c = 0
    else:
        c += 1
print(p)

Solution (Python):
if __name__ == '__main__':
    STR = input()
    ans = ''
    for i in range(0, STR.__len__(), 2):
        ans += STR[i:i+1]
    print(ans)

Solution (Python):
print(str(input())[::2])

Solution (Python):
s=input()
print(s[::2])

Solution (Python):
s = input()
l = len(s)
for i in range(l):
  if i % 2 == 0:
    print(s[i], end='')

Solution (Python):


print(input()[::2])

Solution (Python):
s=input()
ans=""
for i,word in enumerate(s):
    if i%2==0:
        ans+=word
print(ans)

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[::2])

Solution (Python):
s = input();print(s[::2]);

Solution (Python):
print(str(input())[::2])

Solution (Python):


s=raw_input()
res=''
for i in xrange(len(s)):
 if i%2==0:
  res+=s[i]
print res

Solution (Python):

"""

"""



if __name__ == '__main__':
    txt = input()
    result = txt[::2]
    print(result)

Solution (Python):
print(input()[::2])

Solution (Python):
s=str(input())
L=len(s)
ans=''
for i in range(0,L,2):
    ans += s[i]

print(ans)

Solution (Python):
print("".join([j for i,j in enumerate(input()) if i%2==0]))

Solution (Python):
s = input()
hoge =list(s)

moji = ''

for num in range(len(s)):
    if num%2 == 0:
        moji += hoge[num]
    continue

print(moji)

Solution (Python):
a = raw_input().strip()
ans = ''
counter = 1
for x in a:
	if counter % 2 == 1:
		ans += x
	counter += 1
print(ans)

Solution (Python):
print(input()[::2])

Solution (Python):
a=raw_input()
b=list(a)
c=1
ans=""
for i in b:
  if c%2==1:
    ans+=i
  c+=1
print ans

Solution (Python):
s = raw_input()

ans = ""

for i in range(len(s)):
    if ((i + 1) % 2) != 0:
        ans += s[i]

print ans

Solution (Python):
input_line1 = raw_input()
extract1 = input_line1[::2]
print(extract1)

Solution (Python):
print(input()[::2])

Solution (Python):
st = str(input())
result = [st[i] for i in range(len(st)) if i%2 == 0]
print("".join(result))

Solution (Python):
s = input()
for i, e in enumerate(s):
    if i % 2 == 0:
        print(e, end="")
print("")

Solution (Python):
s=input()
r=""
for i in range(len(s)):
    if i%2==0:
        r+=s[i]
print(r)

Solution (Python):
s = str(input())
print(s[0::2])

Solution (Python):
import sys
retsu = list(input())
n = len(retsu)
if n%2== 1:
    a = n // 2 + 1
    for i in range(a):
        sys.stdout.write(retsu[i*2])
else:
    a = n // 2
    for i in range(a):
        sys.stdout.write(retsu[i*2])

Solution (Python):
def b():
    s = input()
    print(s[::2])

b()

Solution (Python):
S = input()

a = ""

for i in range(0, len(S), 2):
    a = a + S[i]

print(a)

Solution (Python):
s=input()
l=[x for x in s[::2]]
print("".join(l))

Solution (Python):


string = input()

res = ""
for i, char in enumerate(string):
    if i % 2 == 0:
        res += char
print (res)

Solution (Python):
import sys

def main():
    S = sys.stdin.readline()[:-1]
    print(S[::2])

if __name__ == '__main__':
    main()

Solution (Python):


s=map(str,input().strip())
ans=''
for num,moji in enumerate(s):
    if num%2==0:
        ans+=moji

print(ans)

Solution (Python):
myinput=input()
print(myinput[::2])

Solution (Python):
s = input()
ans = ""
for i in range(len(s)):
  if(i % 2 == 0):
    ans = ans + s[i]
    
print(ans)

Solution (Python):
import sys
a = sys.stdin.readline().strip()
print (a[::2])

Solution (Python):
s = input()

for i,c in enumerate(s):
  if i % 2 == 0:
    print(c, end="")

Solution (Python):
a = raw_input()
s = ""
for i in range(0, len(a), 2 ):
	s = s + a[i]
print s

Solution (Python):
s = input()
t = 0
for i,j in enumerate(s):
   if i % 2 == 0:
      print(s[i],end="")

Solution (Python):
s=input()
print(s[::2])

Solution (Python):
import sys




def read_int_list():
    return list(map(int, input().split()))


def read_str_list():
    return input().split()


def read_int():
    return int(input())


def read_str():
    return input()


def main():
    s = read_str()
    res = s[0::2]
    print(res)


main()

Solution (Python):
def read_line(*types): return [f(a) for a, f in zip(input().split(), types)]

s, = read_line(str)

for i in range(len(s)):
    if i % 2 == 0:
        print(s[i], end='')

Solution (Python):
def getStrangeString(s):
    res = ""
    for i in range(len(s)):
        if i%2 == 0:
            res += s[i]
    return res
print(getStrangeString(input()))

Solution (Python):
S = input()
print(S[0:len(S):2])

Solution (Python):
s=input()
for i in range(len(s)):
    if i%2==0:
        print(s[i],end="")
print()

Solution (Python):
s = input()
a = ""

for i in range(0,len(s),2):
    a = a+s[i]
    
print(a)

Solution (Python):
print(input()[::2])

Solution (Python):
a=input()
count = 1
li=[]
for char in list(a):
    if count % 2 != 0:
        li.append(char)
        count+=1
    else:
        count+=1
b="".join(li)
print(b)

Solution (Python):
S = input()
arr = []
for i in range(len(S)):
    if i%2 == 0:
        arr.append(S[i])
print(''.join(arr))

Solution (Python):
str = input()
print (str[::2])

Solution (Python):
S = input()

result = ""

for i in range(len(S)):
    if i % 2 == 0:
        result += S[i]

print(result)

Solution (Python):

s = input()
n = len(s)

out = ""
for i in range(0, n, 2):
    out += s[i]
print(out)

Solution (Python):
s = input()
line = s[::2]
print(line)

Solution (Python):
def solve():
    s = input()
    S = s[::2]
    print(S)

if __name__ == '__main__':
    solve()

Solution (Python):
s=list(raw_input())

A=''
for i in range(len(s)):
	if i%2==0:
		A+=s[i]

print A

Solution (Python):
S = input()
ans=[]
for i in range(len(S)):
    if i % 2 == 0:
        ans.append(S[i])
print("".join(ans))

Solution (Python):


import sys

def main(argv):
    for line in sys.stdin:
        output = []
        for i, c in enumerate(line.rstrip("\n")):
            if i % 2 == 0:
                output.append(c)
        print("".join(output))

if __name__ == "__main__":
    main(sys.argv)

Solution (Python):
def B_OddString(s):
    ans = ''
    for i in range(len(s)):
        if i % 2 == 0:
            ans += s[i]
    return ans

s = input()
print(B_OddString(s))

Solution (Python):
tmp=map(str, raw_input())

arr=[]
for n,i in enumerate(tmp):
    if n%2==0:
        arr.append(i)

print "".join(arr)

Solution (Python):
s = input()

print(s[::2])

Solution (Python):
s = input()
l = len(s)
ans = []
for i in range(l):
    if i % 2 == 0:
        ans.append(s[i])
s = "".join(ans)
print(s)

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
s = input()
c = 0
ans = []
for i in s:
    if c % 2 == 0:
        ans.append(i)
    c+=1
        
print(''.join(ans))

Solution (Python):
s=raw_input()

print s[0::2]

Solution (Python):
s = input()		

for i, x in enumerate(s):
	if i%2==0:
		print(x, end="")

print("")

Solution (Python):
nm = input().strip()

print(nm[::2])

Solution (Python):
def solve():
    s = list(input())
    s_odd = s[::2]
    print("".join(s_odd))

   
solve()

Solution (Python):
def main():
    S = input()
    print(S[::2])

main()

Solution (Python):
k = input()
print(k[::2])

Solution (Python):
s=input()
ans=''
for i in range(0, len(s), 2) :
    ans+=s[i]
print(ans)

Solution (Python):
s=input()

print(s[0::2])

Solution (Python):
word = input()

answer = ''

for i in range(0, len(word), 2):
    answer += word[i]

print(answer)

Solution (Python):
s = input()
print(s[::2])

Solution (Python):
s = input()
for i in range(0, len(s), 2):
	print(s[i], end = '')

Solution (Python):
s = input().strip()
for i, c in enumerate(s):
  if i%2 == 0:
    print(c,end='')
print()

Solution (Python):
s = input()
result = "" 
for i in range(0, len(s), 2):
    result += s[i]
    
print(result)

Solution (Python):
s=input()
for i in range(len(s)):
    if i%2==0:print(s[i],end="")

Solution (Python):
s = input()
l = []
for i in range(len(s)):
    if i % 2 == 0:
        l.append(s[i])

print(''.join(l))

Solution (Python):
s = input()
o = ""
for i, ss in enumerate(s):
    if i % 2 == 0:
        o = o + ss
print(o)

Solution (Python):
print("".join(input()[0::2]))

Solution (Python):
def main():
    print(''.join([c for c in input()[::2]]))


if __name__ == "__main__":
    main()

Solution (Python):
s = input()
t = ""
for i in range(0, len(s), 2):
    t += s[i]
print(t)

Solution (Python):
s = input()
print(''.join([c for i, c in enumerate(s) if i % 2 == 0]))

Solution (Python):
s = input()
print(''.join(s[0::2]))

Solution (Python):



s = raw_input()

ans = ""

i = 0
for i in range(len(s)):
    if i % 2 == 1:
        pass
    else:
        ans += s[i]


print ans

Solution (Python):
import sys
S = input()

for i in range(len(S)):
    if i % 2 == 0:
        sys.stdout.write(S[i])
sys.stdout.write("\n")

Solution (Python):
s = input()

for i in range(0,len(s),2):
    print(s[i],end="")
print()

Solution (Python):
S = input()
ans = ""

for i in range(0, len(S), 2):
    ans += S[i]

print(ans)

Solution (Python):
s = input()
ans = ''
for i in range(len(s)):
    if i % 2 == 0:
        ans += s[i] 
print(ans)

Solution (Python):
temp = input().split(" ")
mojis = list(temp[0])
ans = ""
for a in range(len(mojis)):
    if a % 2 == 0:
        ans = ans + mojis[a]
print(ans)

Solution (Python):
S = input()

res = ""

for i, v in enumerate(S):
    if i % 2 == 0:
        res += v

print(res)

Solution (Python):


class Stdin:
    @staticmethod
    def read_line(converter=str):
        return [converter(x) for x in input().split()]
    
    @staticmethod
    def read_lines(n, converter=str):
        result = list()
        for _ in range(n):
            result.append(Stdin.read_line(converter))
        return result
    
    @staticmethod
    def convert(data, converter):
        assert(len(data) == len(converter))
        return tuple(map(lambda x, f: f(x), data, converter))

    @staticmethod
    def convert_lines(datas, n, converter):
        return [converter(data, n, converter) for data in datas]


def main():
    s = input()
    r = "".join([c for (i,c) in enumerate(s) if i % 2 == 0])
    print(r)

if __name__ == "__main__":
    main()

Solution (Python):
from sys import stdin
a = stdin.readline().strip()
ans = ""
l = len(a)
for i in xrange(l):
 if i%2==0:
  ans += a[i]
print ans

Solution (Python):
s = input()
a = s[0::2]
print(a)

Solution (Python):
s = input()
for i in range(len(s)):
    if i % 2 == 0:
        print(s[i], end="")
print("")

Solution (Python):

s = raw_input()
print s[0::2]

Solution (Python):
print(input()[::2])

Solution (Python):
print(input()[::2])

Solution (Python):

def get_ln_inputs():
    return input().split()


def get_ln_int_inputs():
    return list(map(int, get_ln_inputs()))


def main():
    print(get_ln_inputs()[0][::2])


main()

Solution (Python):
print(input()[0::2])

Solution (Python):
s = input()
ss = [s_ for idx, s_ in enumerate(list(s)) if idx % 2 == 0]
print(''.join(ss))