#include<bits/stdc++.h>
#define int long long
#define ii pair<int,int>
using namespace std;
const int maxn = 1e5 + 5;
int n, k, ans;
int f[maxn], sz[maxn], mark[maxn];
vector<ii> adj[maxn], a;
void upd(int x, int val)
{
x++;
for (int i = x; i <= n + 1; i += i & -i)
f[i] += val;
}
int get(int x)
{
x++;
int ans = 0;
for (int i = x; i > 0; i -= i & -i)
ans += f[i];
return ans;
}
void get_size(int x, int p)
{
sz[x] = 1;
for (auto [i, j] : adj[x])
if (i != p && !mark[i])
get_size(i, x),
sz[x] += sz[i];
}
int find(int x, int p, int half)
{
for (auto [i, j] : adj[x])
if (i != p && !mark[i] && sz[i] > half)
return find(i, x, half);
return x;
}
int cal()
{
sort(a.begin(), a.end());
int ans = 0;
for (auto &[mx, len] : a)
{
int q = min(n, mx - len - k);
ans += get(q);
upd(len, 1);
}
for (auto &[mx, len] : a)
upd(len, -1);
a.clear();
return ans;
}
void dfs(int x, int p, int mx, int len)
{
a.emplace_back(mx, len);
for (auto [i, j] : adj[x])
if (i != p && !mark[i])
dfs(i, x, max(mx, j), len + 1);
}
void solve(int x = 1)
{
get_size(x, x);
x = find(x, x, sz[x] / 2);
mark[x] = 1;
dfs(x, x, 0, 0);
ans += cal();
for (auto [i, j] : adj[x]) if (!mark[i])
dfs(i, x, j, 1),
ans -= cal();
for (auto [i, j] : adj[x])
if (!mark[i])
solve(i);
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
// freopen("test.inp", "r", stdin);
// freopen("test.out", "w", stdout);
cin >> n >> k;
for (int i = 1, u, v, w; i < n; i++)
cin >> u >> v >> w,
adj[u].emplace_back(v, w),
adj[v].emplace_back(u, w);
solve();
cout << ans * 2;
}
