#include<bits/stdc++.h>
using namespace std;
string s,s1,ans;
int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n;cin>>n;
    for(int i=1;i<=n;i++)
    {
    	char c;cin>>c;
    	s+=c;
	}
    s1=s;
    reverse(s1.begin(),s1.end());
    while(s.size())
    {
    	if(s<=s1)
    	{
    		ans+=s[0];
    		s.erase(s.begin());
    		s1.pop_back();
		}
		else
		{
    		ans+=s1[0];
    		s1.erase(s1.begin());
    		s.pop_back();
		}
	}
	for(int i=0;i<ans.size();i++)
    {
        if(i%80==0&&i!=0)cout<<endl;
        cout<<ans[i];
    }
    return 0;
}