#include <bits/stdc++.h>   using namespace std;   int main() {     int n, x;     cin >> n;     x = (n + 1) / 2;     string s, even, odd;     cin >> s;     for (int i = 0; i < n; i++) {       if (i % 2 == 0)         odd.push_back(s[i]);       else         even.push_back(s[i]);     }     if (n <= 2) {       cout << s << endl;     } else {       if (n % 2 == 0) {         reverse(odd.begin(), odd.end());         for (int i = 0; i < x; i++) {           odd.push_back(even[i]);         }         even = odd;       } else if (n % 2 == 1) {         reverse(even.begin(), even.end());         for (int i = 0; i < x; i++) {           even.push_back(odd[i]);         }       }       cout << even << endl;     }     return 0;   }   