sicily 1031

#include <iostream>
#include <cstring>
#include <map>
#include <string>
using namespace std;
int n;
int places;
map<string, int> m;
int adj[2010][2010];
bool isVis[1000];
int lowCost[1000];
int main() {
	int cases;
	cin >> cases;
	string source, des;
	map<string, int>::iterator iter;
	int a, b;
	int len;
	while(cases--) {
		cin >> n;
		places = 0;
		m.clear();
		memset(adj, -1, sizeof(adj));
		memset(isVis, false, sizeof(isVis));
		memset(lowCost, 0, sizeof(lowCost));
		for(int i = 0; i < n; i++) {
			cin >> source >> des >> len;
			if((iter = m.find(source)) != m.end())
				a = iter->second;
			else {
				a = places++;
				m.insert(make_pair(source, a));
			}
			if((iter = m.find(des)) != m.end())
				b = iter->second;
			else {
				b = places++;
				m.insert(make_pair(des, b));
			}
			adj[a][b] = adj[b][a] = len;
		}
		cin >> source >> des;
		if(source == des) {
			cout << "0/n";
			continue;
		}
		if((iter = m.find(source)) != m.end())
			a = iter->second;
		else {
			cout << "-1/n";
			continue;
		}
		if((iter = m.find(des)) != m.end())
			b = iter->second;
		else {
			cout << "-1/n";
			continue;
		}
		isVis[a] = true;
		for(int i = 0; i < places; i++) {
			lowCost[i] = adj[a][i];
		}
		while(1) {
			int max = 100000000;
			int index = a;
			for(int i = 0; i < places; i++) {
				if(!isVis[i] && lowCost[i] != -1 && lowCost[i] < max) {
					max = lowCost[i];
					index = i;
				}
			}
			if(index == b) {
				cout << lowCost[b] << endl;
				break;
			}
			if(index == a) {
				cout << "-1" << endl;
				break;
			}
			isVis[index] = true;
			for(int i = 0; i < places; i++) {
				if(!isVis[i] && adj[index][i] != -1) {
					if(lowCost[i] == -1 || lowCost[i] > adj[index][i] + lowCost[index]) {
						lowCost[i] = adj[index][i] + lowCost[index];
					}
				}
			}
		}
	}
	return 0;
}