func main()
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var s: int :: cui@inputInt()
	var g: int :: cui@inputInt()
	
	var f: []int :: #[m]int
	var t: []int :: #[m]int
	for i(0, m - 1)
		do f[i] :: cui@inputInt()
		do t[i] :: cui@inputInt()
	end for
	
	var u: int :: cui@inputInt()
	var ng: dict<int, bool> :: #dict<int, bool>
	for(1, u)
		var i: int :: cui@inputInt()
		do ng.add(i, true)
	end for
	
	var uni: UnionFind :: (#UnionFind).init(n + 1)
	
	for i(0, m - 1)
		var fi: int :: f[i]
		var ti: int :: t[i]
		if(!ng.get(fi, &) & !ng.get(ti, &))
			do uni.unite(fi, ti)
		end if
	end for
	
	var ans: bool :: uni.same(s, g)
	do cui@print((ans ?("Yes", "No")) ~ "\n")
	
	class UnionFind()
		var parents: []int
		+func init(n: int): UnionFind
			do me.parents :: [-1].repeat(n)
			ret me
		end func
		+func size(x: int): int
			ret -me.parents[me.root(x)]
		end func
		+func same(x: int, y: int): bool
			ret me.root(x) = me.root(y)
		end func
		+func unite(x: int, y: int): bool
			do x :: me.root(x)
			do y :: me.root(y)
			if(x = y)
				ret false
			end if
			if(me.size(x) < me.size(y))
				do me.parents[y] :+ me.parents[x]
				do me.parents[x] :: y
			else
				do me.parents[x] :+ me.parents[y]
				do me.parents[y] :: x
			end if
			ret true
		end func
		
		func root(x: int): int
			if(me.parents[x] < 0)
				ret x
			else
				do me.parents[x] :: me.root(me.parents[x])
				ret me.parents[x]
			end if
		end func
	end class
end func