#include<bits/stdc++.h>
using namespace std;
struct node {
char l,r;
} a[300];
char b,c;
int n;
void dfs(int x) {
cout<<(char)x;
if(a[x].l!='*') {
dfs(a[x].l);
}
if(a[x].r!='*') {
dfs(a[x].r);
}
}
int main() {
cin>>n;
for(int i = 1; i <= n; i++) {
cin>>b;
if(i==1) {
c=b;
}
cin>>a[b].l;
cin>>a[b].r;
}
dfs(c);
}