1 // Problem#: 8768
 2 // Submission#: 2606406
 3 // The source code is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
 4 // URI: http://creativecommons.org/licenses/by-nc-sa/3.0/
 5 // All Copyright reserved by Informatic Lab of Sun Yat-sen University
 6 #include<iostream>
 7 #include<string>
 8 #include<vector>
 9 #include <algorithm>
10 #include<cstdlib>
11 using namespace std;
12 
13 vector<string> str;
14 int main(){
15     int T;
16     string input;
17 
18     while(cin>>T && T != 0){
19         cin>>input;
20         int row = input.size()/T;
21         str.resize(row);
22         for(int i=0;i<row;i++){
23             string temp;
24             temp =input.substr(0+i*T,T);
25             if(i%2==1){
26                 reverse(temp.begin(),temp.end());
27             }
28             str[i]=temp;
29         }
30         for(int i=0;i<T;i++){
31             for(int j=0;j<row;j++)
32                 cout<<str[j][i];
33         }
34         cout<<endl;
35     }
36     return 0;
37 }