DFS
#include<iostream>
#include<string>
#include<cstring>
#include<vector>
using namespace std;
const int maxn = 50;
struct Node {
string data;
int lchild, rchild;
}node[maxn];
bool isroot[maxn];
int root = 0;
string DFS(int index)
{
if (index == -1)return "";
else
{
if (node[index].rchild != -1)
{
node[index].data = DFS(node[index].lchild) + node[index].data + DFS(node[index].rchild);
if (index != root)node[index].data = "(" + node[index].data + ")";
}
return node[index].data;
}
}
int main()
{
int n;
scanf("%d", &n);
getchar();
for (int i = 1; i <= n; i++)
{
cin >> node[i].data >> node[i].lchild >> node[i].rchild;
if (node[i].lchild != -1)isroot[node[i].lchild] = true;
if (node[i].rchild != -1)isroot[node[i].rchild] = true;
}
for (int i = 1; i <= n; i++)
{
if (isroot[i] == false)
{
root = i;
break;
}
}
cout<<DFS(root);
return 0;
}
