#include "race.h"
#include "bits/stdc++.h"
using namespace std;
const int MXN = 2e5 + 5;
const int MXK = 105;
const long long MXV = 1e7 + 5;
vector<pair<int, long long>> adj[MXN];
long long dp[MXN][MXK];
void dfs(int u, int p) {
dp[u][0] = 0;
for (auto &[v, w] : adj[u]) {
if (v == p) {
continue;
}
for (long long i = MXK - 1; i >= w; --i) {
if (dp[u][i - w] != MXV) {
dp[v][i] = min(dp[v][i], dp[u][i - w] + 1);
}
}
dfs(v, u);
}
}
int best_path(int N, int K, int H[][2], int L[]) {
for (int i = 0; i < N - 1; ++i) {
adj[H[i][0]].push_back({H[i][1], L[i]});
adj[H[i][1]].push_back({H[i][0], L[i]});
}
for (int i = 0; i < N; ++i) {
for (long long j = 0; j <= K; ++j) {
dp[i][j] = MXV;
}
}
dfs(0, -1);
long long ans = MXV;
for (int i = 0; i < N; ++i) {
if (dp[i][K] != MXV) {
ans = min(ans, dp[i][K]);
}
}
return (ans == MXV ? -1 : ans);
}
