#include <bits/stdc++.h>
using namespace std;
int n, cnt, c;
string second, ans;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> second;
  if (n % 2)
    c = 1;
  else
    c = 1;
  for (int i = 0; i < second.size(); ++i) ans += " ";
  for (int i = second.size() - 1; i >= 0; --i) {
    if (c) {
      ans[n - 1] = second[i];
      c = 0;
      n--;
    } else {
      ans[cnt] = second[i];
      c = 1;
      cnt++;
    }
  }
  cout << ans;
}
