#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n,t;
    cin >> n;
    string ss;
    vector<string> s(2);

    for(int i = 0;i < n;i++){
        cin >> t >> ss;
        s[t] += ss;
    }
    reverse(s[1].begin(),s[1].end());
    cout << s[1] <<s[0] << endl;
}