#include <iostream>
using namespace std;
struct treenode{
    char l,r;char val;
};
treenode a[26+5];
void pre(char root){
    if(root=='*')return ;
    cout<<root;
    pre(a[root-'a'].l);
    pre(a[root-'a'].r);
}
int main(){
    int n;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a[i].val>>a[i].l>>a[i].r;
    }
    pre(a[0].val);
    cout<<"\n";
}