package main

import . "fmt"

func main() {
	var n,m,s,g int
	Scan(&n,&m,&s,&g)
	graph := make([][]int, n+1)
	for ; m > 0; m-- {
		var f,t int
		Scan(&f,&t)
		graph[f] = append(graph[f], t)
		graph[t] = append(graph[t], f)
	}
	var u int
	Scan(&u)
	for ; u > 0; u-- {
		var i int
		Scan(&i)
		graph[i] = nil
	}
	visited := make([]bool, n+1)
	visited[s] = true
	stk := []int{s}
	for len(stk) > 0 {
		l := len(stk)-1
		p := stk[l]
		stk = stk[:l]
		if p == g {
			Println("Yes")
			return
		}
		for _, next := range graph[p] {
			if visited[next] {
				continue
			}
			visited[next] = true
			stk = append(stk, next)
		}
	}
	Println("No")
}