#include <bits/stdc++.h>
using namespace std;
union char_int
{
	int i_num;
	char c_num;
};
struct trees
{
	char c;
	char_int l,r;
}tr[30];
int n;
int num[256];
char ls;
void cha_i(int i)
{
	tr[i].l.i_num=num[int(tr[i].l.c_num)];
	tr[i].r.i_num=num[int(tr[i].r.c_num)];
}
void cha()
{
	for(int i=0;i<n;i++)cha_i(i);
}
/*
void read(int &a)
{
    char c;
    int x=1;
    a=0;
    while(!isdigit(c)){c=getchar();if(c=='-')x=-1;}
    while(isdigit(c))a=(a<<3)+(a<<1)+(c^48),c=getchar();
    a*=x;
}
void out(int a)
{
    if(a<0)
	{
		putchar('-');
		out(-a);
	}
    else if(a<10)
    {
    	putchar(a+'0');
    	return;
	}
	else
	{
		out(a/10);
		putchar(a%10+'0'); 
	}
}
*/
void I__(int i=0)
{
	putchar(tr[i].c);
	if(tr[i].l.i_num)I__(tr[i].l.i_num);
	if(tr[i].r.i_num)I__(tr[i].r.i_num);
}
int main()
{
//	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	scanf("%d\n",&n);
	for(int i=0;i<n;i++)
	{
		ls=getchar();
		num[int(ls)]=i;
		tr[i].c=ls;
		ls=getchar();
		tr[i].l.c_num=ls;
		ls=getchar();
		tr[i].r.c_num=ls;
		ls=getchar();
	}
	cha();
	I__();
	return 0;
}