#include "bits/stdc++.h"
#define MAX_N 500000
#define ff first
#define ss second
using namespace std;
const int Na = 1e3 + 5;
vector<pair<int, int>> adj[Na];
int vis[Na], dis[Na], edge[Na];
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]});
queue<int> q;
int answer = INT_MAX;
for(int i = 0; i < n; ++i){
for(int j = 0; j < n; ++j)
vis[j] = 0, dis[j] = 0, edge[j] = 0;
while(!q.empty())
q.pop();
q.push(i);
vis[i] = 1;
while(!q.empty()){
int x = q.front();
q.pop();
for(auto &to : adj[x])
if(!vis[to.ff]){
dis[to.ff] = dis[x] + to.ss;
edge[to.ff] = edge[x] + 1;
vis[to.ff] = 1;
q.push(to.ff);
}
}
for(int j = 0; j < n; ++j)
if(dis[j] == k)
answer = min(answer, edge[j]);
}
return (answer == INT_MAX ? -1 : answer);
}
//static int N, K;
//static int H[MAX_N][2];
//static int L[MAX_N];
//static int solution;
//
//inline
//void my_assert(int e) {if (!e) abort();}
//
//void read_input()
//{
// int i;
// my_assert(2==scanf("%d %d",&N,&K));
// for(i=0; i<N-1; i++)
// my_assert(3==scanf("%d %d %d",&H[i][0],&H[i][1],&L[i]));
// my_assert(1==scanf("%d",&solution));
//}
//
//int main() {
// int ans;
// read_input();
// ans = best_path(N,K,H,L);
// if(ans==solution)
// printf("Correct.\n");
// else
// printf("Incorrect. Returned %d, Expected %d.\n",ans,solution);
//
// return 0;
//}
