#include "bits/stdc++.h"
using namespace std;

#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl

typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
const int inf = 1000000001;
const ll INF = 2e18 * 2;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };

int main() {
	int i, j;
	int n, m;
	cin >> n >> m;
	vi a(n);
	for (i = 0; i < n; i++) {
		cin >> a[i];
	}
	vii edge(m, vi(2));
	for (i = 0; i < m; i++) {
		cin >> edge[i][0] >> edge[i][1];
		edge[i][0]--;
		edge[i][1]--;
	}
	for (i = 0; i < m; i++) {
		for (j = i + 1; j < m; j++) {
			for (int k = 0; k < 2; k++) {
				for (int l = 0; l < 2; l++) {
					if (edge[i][k] == edge[j][l]) {
						int a0 = a[edge[i][1 - k]];
						int a1 = a[edge[i][k]];
						int a2 = a[edge[j][1 - l]];
						if ((a1 - a0)*(a1 - a2) > 0 && a0 != a2) {
							cout << "YES" << endl;
							return 0;
						}
					}
				}
			}
		}
	}
	cout << "NO" << endl;
}