#include <iostream>#include <cstdlib>#include <cstdio>#include <cstring>using namespace std;#define maxm 105#define maxn 105struct Edge{ int v, next; double rate, commission;}edge[maxm * 2];int n, m;int s;int head[maxn];double v;double dist[maxn];bool in_queue[maxn];int push_cnt[maxn];int q[maxn];int edge_cnt;void addedge(int a, int b, double r, double c){ edge[edge_cnt].v = b; edge[edge_cnt].next = head[a]; edge[edge_cnt].rate = r; edge[edge_cnt].commission = c; head[a] = edge_cnt++;}void input(){ edge_cnt = 0; memset(head, -1, sizeof(head)); scanf("%d%d%d%lf", &n, &m, &s, &v); s--; for (int i = 0; i < m; i++) { int a, b; double r, c; scanf("%d%d", &a, &b); a--; b--; scanf("%lf%lf", &r, &c); addedge(a, b, r, c); scanf("%lf%lf", &r, &c); addedge(b, a, r, c); }}bool spfa(int s){ for (int i = 0; i < n; i++) dist[i] = -1; dist[s] = v; memset(in_queue, 0, sizeof(in_queue)); memset(push_cnt, 0, sizeof(push_cnt)); int front, rear; front = 0; rear = 0; q[rear++] = s; in_queue[s] = true; push_cnt[s] = 1; while (front != rear) { int u = q[front++]; if (front == maxn) front = 0; in_queue[u] = false; double cur = dist[u]; for (int i = head[u]; ~i; i = edge[i].next) { int v = edge[i].v; double r = edge[i].rate; double c = edge[i].commission; double temp = (cur - c) * r; if (temp > dist[v]) { dist[v] = temp; if (in_queue[v]) continue; q[rear++] = v; if (rear == maxn) rear = 0; in_queue[v] = true; push_cnt[v]++; if (push_cnt[v] > n) return true; } } if (dist[s] > v) return true; } return false;}int main(){ input(); if (spfa(s)) puts("YES"); else puts("NO"); return 0;}
