#include<bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define sz(a) (int)a.size()
#define ll long long
const int N = 1e5;
const int T = 20;
vector <pair <int, int> > g[N];
int n, k;
int used[N];
int _sz[N];
vector <int> h_p[N];
vector <int> Trees[N];
ll ans = 0;
void update(int ind, int v, int l, int r, int x, int c)
{
Trees[ind][v] += c;
if(l == r)
{
return;
}
if(x <= (r + l) / 2)
{
update(ind, v * 2, l, (r + l) / 2, x, c);
}
else
{
update(ind, v * 2 + 1, (r + l) / 2 + 1, r, x, c);
}
}
int get_ans(int ind, int v, int l, int r, int al, int ar)
{
if(al > ar)
{
return 0;
}
if(l >= al && r <= ar)
{
return Trees[ind][v];
}
if(l <= ar && r >= al)
{
return get_ans(ind, v * 2, l, (r + l) / 2, al, ar) + get_ans(ind, v * 2 + 1, (r + l) / 2 + 1, r, al, ar);
}
return 0;
}
int coun[N];
void dfs(int v, int p = -1)
{
_sz[v] = 1;
for(auto to : g[v])
{
if(!used[to.X] && to.X != p)
{
dfs(to.X, v);
_sz[v] += _sz[to.X];
}
}
}
int centroid(int v, int sz1, int p = -1)
{
for(auto to : g[v])
{
if(!used[to.X] && to.X != p && _sz[to.X] * 2 > sz1)
{
return centroid(to.X, sz1, v);
}
}
return v;
}
int par[N];
int H[N];
vector <pair <int, int> > vec;
vector <int> h_t[N];
void go_to(int v, int maxd, int h, int p = -1)
{
if(maxd >= h)
{
ans++;
}
h_t[par[v]].push_back(h);
H[v] = h;
coun[par[v]]++;
vec.push_back({maxd, v});
for(auto to : g[v])
{
if(used[to.X] || to.X == p)
{
continue;
}
par[to.X] = par[v];
go_to(to.X, max(maxd, to.Y), h + 1, v);
}
}
void build(int v)
{
dfs(v);
v = centroid(v, _sz[v]);
used[v] = 1;
for(auto to : g[v])
{
h_t[to.X].clear();
coun[to.X] = 0;
Trees[to.X + 1].clear();
if(!used[to.X])
{
par[to.X] = to.X;
go_to(to.X, to.Y, 1);
sort(h_t[to.X].begin(), h_t[to.X].end());
Trees[to.X + 1].resize(4 * coun[to.X]);
}
}
sort(vec.begin(), vec.end());
for(auto p : vec)
{
int t_l1 = p.X - H[p.Y];
int t_l2 = upper_bound(h_t[par[p.Y]].begin(), h_t[par[p.Y]].end(), t_l1) - h_t[par[p.Y]].begin();
t_l2--;
ans += get_ans(0, 1, 0, N - 1, 0, t_l1) - get_ans(par[p.Y] + 1, 1, 0, coun[par[p.Y]] - 1, 0, t_l2);
update(0, 1, 0, N - 1, H[p.Y], 1);
int d1 = lower_bound(h_t[par[p.Y]].begin(), h_t[par[p.Y]].end(), H[p.Y]) - h_t[par[p.Y]].begin();
update(par[p.Y] + 1, 1, 0, coun[par[p.Y]] - 1, d1, 1);
}
// cout << v << " " << ans << "\n";
for(auto p : vec)
{
int t_l1 = p.X - H[p.Y];
int t_l2 = upper_bound(h_t[par[p.Y]].begin(), h_t[par[p.Y]].end(), t_l1) - h_t[par[p.Y]].begin();
t_l2--;
update(0, 1, 0, N - 1, H[p.Y], -1);
int d1 = lower_bound(h_t[par[p.Y]].begin(), h_t[par[p.Y]].end(), H[p.Y]) - h_t[par[p.Y]].begin();
update(par[p.Y] + 1, 1, 0, coun[par[p.Y]] - 1, d1, -1);
}
vec.clear();
for(auto to : g[v])
{
if(!used[to.X])
{
build(to.X);
}
}
}
signed main()
{
// ifstream cin("input1.txt.4c");
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> k;
for(int i = 0; i < n - 1; i++)
{
int x, y, w;
cin >> x >> y >> w;
x--;
y--;
w -= k;
g[x].push_back({y, w});
g[y].push_back({x, w});
}
Trees[0].resize(4 * N);
build(0);
cout << ans * 2;
return 0;
}
