#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  char str[2001], answer[2001];
  cin >> n;
  if (n % 2 != 0) {
    int middle = n - (n / 2);
    for (int i = 1; i <= n; i++) {
      cin >> str[i];
    }
    int k = n, left, right;
    middle = k - (k / 2);
    left = middle - 1;
    right = middle + 1;
    answer[middle] = str[1];
    for (int i = 2; i <= n; i++) {
      if (i % 2 == 0) {
        answer[left] = str[i];
        left--;
      } else if (i % 2 != 0) {
        answer[right] = str[i];
        right++;
      }
    }
    for (int i = 1; i <= n; i++) cout << answer[i];
  } else {
    for (int i = 1; i <= n; i++) {
      cin >> str[i];
    }
    int k = n, left, right;
    int middle = k / 2;
    left = middle - 1;
    right = middle + 1;
    answer[middle] = str[1];
    for (int i = 2; i <= n; i++) {
      if (i % 2 != 0) {
        answer[left] = str[i];
        left--;
      } else if (i % 2 == 0) {
        answer[right] = str[i];
        right++;
      }
    }
    for (int i = 1; i <= n; i++) cout << answer[i];
  }
  return 0;
}
