#include<iostream>
#include<string>
#include<cmath>
#include<queue>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<cassert>
#include<functional>
#include<algorithm>
#include<cstdio>
#include<bitset>
#include<unordered_map>
using namespace std;
//---------------------------------------------------
//ライブラリゾーン！！！！
typedef long long ll;
typedef long double ld;
#define str string
#define rep(i,j) for(ll i=0;i<(long long)(j);i++)
#define all(a) (a).begin(),(a).end()
const ll Mod = 1000000007;
const ll gosenchou = 5000000000000000;
short gh[2][4] = { { 0,0,-1,1 },{ -1,1,0,0 } };
struct P {
ll pos, cost;
};
bool operator<(P a, P b) { return a.cost < b.cost; }
bool operator>(P a, P b) { return a.cost > b.cost; }
struct B {//隣接リスト表現
ll to, cost;
};
struct E {//辺の情報を入れる変数
ll from, to, cost;
};
bool operator<(E a, E b) {
return a.cost < b.cost;
}
struct H {
ll x, y;
};
bool operator<(H a, H b) {
if (a.x != b.x) return a.x < b.x;
return a.y < b.y;
}
bool operator>(H a, H b) {
if (a.x != b.x) return a.x > b.x;
return a.y > b.y;
}
bool operator==(H a, H b) {
return a.x == b.x&&a.y == b.y;
}
bool operator!=(H a, H b) {
return a.x != b.x || a.y != b.y;
}
ll gcm(ll i, ll j) {//最大公約数
if (i > j) swap(i, j);
if (i == 0) return j;
return gcm(j%i, i);
}
ld rad(H a, H b) {
return sqrt(pow(a.x - b.x, 2.0) + pow(a.y - b.y, 2.0));
}//rad＝座標上の2点間の距離
ll ari(ll a, ll b, ll c) {
return (a + b)*c / 2;
}//等差数列の和
ll fact(ll x, ll k, ll p) {//最大値、個数、あまり
ll sum = 1;
for (int i = 0; i < k; i++) {
sum *= (x--);
sum %= p;
}
return sum;
}//階乗(正）
ll mod_pow(ll x, ll n, ll p) {
ll res = 1;
while (n > 0) {
if (n & 1) res = res*x%p;
x = x*x%p;
n >>= 1;
}
return res;
}//x^n%p
short ctos(char a) {
return (int)(a - '0');
}
#define int long long
const long long Inf = 4523372036854775807;
const int inf = 15000000000;
//----------------------------------------------------
//++++++++++++++++++++++++++++++++++++++++++++++++++++
int n, m, r, t;
int a[5000][5000];
E b[5000];
vector<int>c[5000];
vector<B>e[5000];
signed main() {
cin >> n >> m >> r >> t;
for (int i = 0; i < m; i++) {
cin >> b[i].from >> b[i].to >> b[i].cost;
e[b[i].from].push_back(B{ b[i].to,b[i].cost });
e[b[i].to].push_back(B{ b[i].from,b[i].cost });
}
priority_queue<P, vector<P>, greater<P>>p;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++)
a[i][j] = inf;
a[i][i] = 0;
p.push(P{ i,0 });
while (!p.empty()) {
P t = p.top(); p.pop();
for (int j = 0; j < e[t.pos].size(); j++) {
if (a[i][e[t.pos][j].to] > a[i][t.pos] + e[t.pos][j].cost) {
a[i][e[t.pos][j].to] = a[i][t.pos] + e[t.pos][j].cost;
p.push(P{ e[t.pos][j].to,a[i][e[t.pos][j].to] });
}
}
}
for (int j = 1; j <= n; j++) {
c[i].push_back(a[i][j]);
}
sort(all(c[i]));
}
int ans = 0;
for (int i = 1; i <= n; i++) {
for (int j = i + 1; j <= n; j++) {
ld o = (ld)a[i][j] / t*r;
if (o == floor(o)) o += 1;
else o = ceil(o);
int u = c[i].size() - (lower_bound(all(c[i]), o) - c[i].begin());
if (r < t) u--;
if (u > 0) ans += u;
u = c[j].size() - (lower_bound(all(c[j]), o) - c[j].begin());
if (r < t) u--;
if (u > 0) ans += u;
}
}
cout << ans << endl;
}