#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
long long min(long long a, long long b) { return (a < b) ? a : b; }
long long max(long long a, long long b) { return (a > b) ? a : b; }
long long fp(long long a, long long b) {
  if (b == 0) return 1;
  long long x = fp(a, b / 2);
  x = (x * x) % mod;
  if (b & 1) x = (x * a) % mod;
  return x;
}
const long long N = 2e5 + 5;
void solve() {
  long long n;
  cin >> n;
  string s;
  cin >> s;
  deque<char> ans;
  long long f = 0;
  if (n % 2 == 0) f ^= 1;
  for (auto i : s) {
    if (f)
      ans.push_front(i);
    else
      ans.push_back(i);
    f ^= 1;
  }
  while (ans.size()) cout << ans.front(), ans.pop_front();
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  srand(time(0));
  long long t = 1;
  for (long long i = 1; i <= t; i++) {
    solve();
  }
}
