#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;


int main() {
    int n;
    cin >> n;

    int t[n];
    char s[n];
    rep(i,n)cin >> t[i] >> s[i];
    drep(i,n)if(t[i] == 1)cout << s[i];
    rep(i,n)if(t[i] == 0)cout << s[i];
    cout << endl;

    return 0;
}