#include "race.h"
#include <bits/stdc++.h>
using namespace std;
vector <pair <int, int>> g[1005];
int ans, k, used[1005];
void dfs(int v, int p = -1, int dep = 0, long long len = 0) {
used[v] = 1;
if (len > k) return;
if (len == k) ans = min(ans, dep);
for (auto i: g[v]) {
if (!used[i.first]) {
dfs(i.first, v, dep + 1, len + i.second);
}
}
}
int best_path(int N, int K, int H[][2], int L[])
{
k = K;
for (int i = 0; i < N; i ++) {
g[H[i][0]].push_back({H[i][1], L[i]});
g[H[i][1]].push_back({H[i][0], L[i]});
}
ans = 1e9;
for (int i = 0; i < N; i ++) {
memset(used, 0, sizeof(used));
dfs(i);
}
if (ans == 1e9) ans = -1;
return ans;
}
