#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2123;
char ans[MAXN];
void decode(string s, int n) {
  if (s.length() % 2) {
    int k = s.length() / 2;
    int j = k;
    ans[k] = s[0];
    k++;
    j--;
    for (int i = 1; i < n; i += 2) {
      ;
      ;
      ans[j--] = s[i];
      ans[k++] = s[i + 1];
    }
  } else {
    int k = (s.length() / 2) - 1;
    int j = k + 1;
    ;
    for (int i = 0; i < n; i += 2) {
      ;
      ;
      ;
      ans[k--] = s[i];
      ans[j++] = s[i + 1];
    }
  }
  ans[s.length()] = 0;
}
int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  int n;
  string s;
  cin >> n >> s;
  decode(s, n);
  ;
  ;
  cout << ans << '\n';
}
