#include <bits/stdc++.h>
using namespace std;
int main() {
  long long i, j, k, x, y, z, fl, sum, count, n, median, par;
  char c[2005], d[2005];
  cin >> n;
  cin.get();
  cin >> c;
  if (n == 2 || n == 1) {
    cout << c << "\n";
    return 0;
  }
  if (n % 2 == 1) {
    median = n / 2;
    fl = 0;
  } else {
    median = (n / 2) - 1;
    fl = 1;
  }
  par = n % 2;
  d[median] = c[0];
  sum = 1;
  for (i = 1; i < n; i++) {
    if (fl == 0) {
      d[median - sum] = c[i];
      fl = 1;
      if (par == 0) sum++;
    } else {
      d[median + sum] = c[i];
      fl = 0;
      if (par == 1) sum++;
    }
  }
  for (i = 0; i < n; i++) cout << d[i];
  cout << "\n";
  return 0;
}
