#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cmath>
#include <cstring>
#include<algorithm>
#include<queue>
#include<map>
#include<stack>
using namespace std;



struct a {
	char  left;
	char right;
};

a ch[140];
void dfs(char c)
{
	printf("%c", c);
	if (ch[c].left != '*')
		dfs(ch[c].left);
	if (ch[c].right != '*')
		dfs(ch[c].right);
	return;

}
int main(void)
{
	
	int n, i, j, k;
	char a1, a2,a3,m;
	
	scanf("%d", &n);
	getchar();
	scanf("%c%c%c", &a1, &ch[a1].left, &ch[a1].right);
	m = a1;
	
	getchar();
	for (i = 2; i <= n; i++)
	{
		scanf("%c%c%c", &a1, &ch[a1].left, &ch[a1].right);
		getchar();
	}

	dfs(m);

	

	return 0;
}