// poj1987

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

#define LL long long

#define MOD 100000000

#define inf 2147483640

#define Pi acos(-1.0)

#define free(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);

using namespace std;

const int maxn=40010;

struct edge {int to,next,w;}e[maxn<<1];

int head[maxn],deep[maxn],d[maxn],size[maxn],f[maxn],vis[maxn];

int n,m,K,cnt,rt,sum,ans;

void link(int u,int v,int w) {

	e[++cnt].to=v;e[cnt].next=head[u];head[u]=cnt;e[cnt].w=w;

	e[++cnt].to=u;e[cnt].next=head[v];head[v]=cnt;e[cnt].w=w;

}

void calroot(int x,int fa) {

	size[x]=1;f[x]=0;

	for (int i=head[x];i;i=e[i].next)

		if (!vis[e[i].to] && e[i].to!=fa) {

			calroot(e[i].to,x);

			size[x]+=size[e[i].to];

			f[x]=max(f[x],size[e[i].to]);

		}

	f[x]=max(f[x],sum-size[x]);

	if (f[x]<f[rt]) rt=x;

}

void caldeep(int x,int fa) {

	deep[++deep[0]]=d[x];

	for (int i=head[x];i;i=e[i].next)

		if (!vis[e[i].to] && e[i].to!=fa) {

			d[e[i].to]=d[x]+e[i].w;

			caldeep(e[i].to,x);

		}

}

int cal(int x,int now) {

	d[x]=now;deep[0]=0;

	caldeep(x,0);

	sort(deep+1,deep+deep[0]+1);

	int t=0;

	for (int l=1,r=deep[0];l<r;) {

		if (deep[l]+deep[r]<=K) t+=r-l,l++;

		else r--;

	}

	return t;

}

void solve(int x) {

	vis[x]=1;

	ans+=cal(x,0);

	for (int i=head[x];i;i=e[i].next) if (!vis[e[i].to]) ans-=cal(e[i].to,e[i].w);

	for (int i=head[x];i;i=e[i].next) if (!vis[e[i].to]) {

			rt=0;sum=size[e[i].to];

			calroot(e[i].to,0);

			solve(rt);

		}

}

int main() {

	scanf("%d%d",&n,&m);

	char ch;

	for (int u,v,w,i=1;i<=m;i++) {

		scanf("%d%d%d %c",&u,&v,&w,&ch);

		if (u==v) continue;

		link(u,v,w);

	}

	scanf("%d",&K);

	rt=0;sum=n;f[0]=inf;

	calroot(1,0);

	solve(rt);

	printf("%d",ans);

	return 0;

}