#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int>> adj[1010];
int dfs(int x, int p, int rem, int l)
{
if (rem == 0)
return l;
if (rem < 0)
return 1010;
int ans = 1010;
for (auto [y, w] : adj[x])
{
if (y == p)
continue;
ans = min(ans, dfs(y, x, rem - w, l + 1));
}
return ans;
}
int best_path(int n, int k, int h[][2], int l[])
{
for (int i = 0; i < n - 1; i++)
{
adj[h[i][0] + 1].emplace_back(h[i][1] + 1, l[i]);
adj[h[i][1] + 1].emplace_back(h[i][0] + 1, l[i]);
}
int ans = n;
for (int i = 1; i <= n; i++)
ans = min(ans, dfs(i, 0, k, 0));
if (ans >= n)
return -1;
else
return ans;
}
