#include <stdio.h>
#include <string.h>

int main(void)
{
  int i, j, k, half;
  char str[256], str2[256], finlaStr[256];
  scanf("%s", str);

  half = strlen(str)/2;

  if(strlen(str) % 2) half++;

  /* Split the string */
  for(i = 0, j = half; j < strlen(str);i++ ,j++)
  {
    str2[i] = str[j];
  }
  str2[i] = '\0';
  str[half] = '\0';

  /* constructing the final string based on the two halves */
  for(i = 0, k = 0; i < half; i++, k += 2)
  {
    finlaStr[k] = str[i];
    finlaStr[k+1] = str2[i];
  }
  finlaStr[k] = '\0';

  printf("%s\n", finlaStr);

  return 0;
}