#include<stdio.h>

 #include<string.h>

 #include<queue>

 using namespace std;

 int head[],point[],next[],size,t[],n,m;

 double r[],c[],dist[];

 bool vis[];

 void add(int a,int b,double r1,double c1){

     point[size]=b;

     r[size]=r1;

     c[size]=c1;

     next[size]=head[a];

     head[a]=size++;

 }

 void spfa(int s,double v){

     int i;

     memset(dist,,sizeof(dist));

     memset(vis,,sizeof(vis));

     memset(t,,sizeof(t));

     dist[s]=v;

     queue<int>q;

     q.push(s);

     vis[s]=;

     bool f=;

     while(!q.empty()){

         if(f)break;

         int u=q.front();

         q.pop();

         vis[u]=;

         for(i=head[u];~i;i=next[i]){

             int j=point[i];

             if(dist[j]<(dist[u]-c[i])*r[i]){

                 dist[j]=(dist[u]-c[i])*r[i];

                 if(!vis[j]){

                     q.push(j);

                     vis[j]=;

                     t[j]++;

                     if(t[j]>n)f=;

                 }

             }

         }

     }

     if(f)printf("YES\n");

     else printf("NO\n");

 }

 int main(){

     int s,i;

     double v;

     while(scanf("%d%d%d%lf",&n,&m,&s,&v)!=EOF){

         memset(head,-,sizeof(head));

         size=;

         for(i=;i<=m;i++){

             int a,b;

             double r1,c1;

             scanf("%d%d%lf%lf",&a,&b,&r1,&c1);

             add(a,b,r1,c1);

             scanf("%lf%lf",&r1,&c1);

             add(b,a,r1,c1);

         }

         spfa(s,v);

     }

     return ;

 }