#include<bits/stdc++.h>
using namespace std;
int main(){
string s1;int n;
(cin>>n).get();
(cin>>s1).get();
int len = s1.length();
int row = len/n;
int zu = len/n;
for(int i=0;i<zu;i++){
if(i%2==1){
reverse(&s1[in],&s1[in+n]);}
}
for(int i=0;i<n;i++){
for(int j=0;j<row;j++){
cout<<s1[i+n*j];
}
}
return 0;
}
