#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
#include <stdio.h>
#include <cmath>
#include <math.h>
#include <math.h>
#include <queue>
#include <stack>
#include <climits>
#include <deque>
#include <ctime>
#include <iomanip>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <fstream>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
#define sor(n) n.begin(), n.end()
#define rsor(n) n.rbegin(), n.rend()
#define mp make_pair
#define files freopen("input.txt", "rt", stdin); freopen("output.txt", "wt", stdout)
#define p(T) pair<T,T>
#define precis(x) cout.precision(x), cout.setf(ios::fixed)
#define SWS ios::sync_with_stdio(false)
#define CT cin.tie(0), cout.tie(0)

vector<vector<int>>f;
map<int, bool>ma;

int main() {
	SWS; CT;
	int n, m;
	cin >> n >> m;

	f.resize(m + n + 2);
	for (int i = 0; i != m; ++i) {
		int u, v;
		cin >> u >> v;

		f[v].push_back(u);
	}

	for (int i = 0; i != n; ++i) {
		int a;
		cin >> a;
		if (i == 0 && f[a].size() == 0) {
			ma[a] = 1;
			continue;
		}
		else if (i == 0 && f[a].size() != 0) {
			cout << "NO";
			//system("pause");
			return 0;
		}
		if (f[a].size() == 0) {
			ma[a] = 1;
			continue;
		}
		for (auto v : f[a]) {
			if (!ma[v]) {
				cout << "NO";
				//system("pause");
				return 0;
			}
		}
		ma[a] = 1;

	}
	cout << "YES";
	//system("pause");
	return 0;
}