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 in C (GCC 5.4.1) (judge verdict: Runtime Error)

#include <stdio.h>
#include <string.h>
int main(){
    char s[1000],str[1000];
    int i,j;
    scanf("%s",s);
    for(i=0;i<strlen(s);i++){
        //for(i=0;i<strlen(s)/2;i+=2)
        if(i%2==0){
            str[j]=s[i];
            j++;
        }
    }
    printf("%s\n",str);
    //printf("\n");
    //printf("%lu %lu\n",strlen(str),strlen(s));
    return 0;
}