#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int,int> pint;
typedef vector<pint> vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=n-1;i>=(0);i--)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define all(v) (v).begin(),(v).end()
#define eall(v) unique(all(v), v.end())
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll INFF = 1e18;

int a[1010];
vector<int> g[1010];

bool f = false;
void dfs(int u, int p, vector<int> v) {
	if(v.size() == 3) {
		if ((v[0] != v[1] && v[1] != v[2] && v[2] != v[0]) &&
			((v[0] < v[1] && v[1] > v[2]) || (v[0] > v[1] && v[1] < v[2]))){
			// printf("%d %d %d\n", v[0], v[1], v[2]);
			f = true;
		}
		return;
	}

	for(auto next : g[u]) {
		if(next == p) continue;
		v.pb(a[next]);
		dfs(next, u, v);
		v.pop_back();
	}
}

int main(void) {
	int n, m; cin >> n >> m;
	rep(i, n) cin >> a[i];
	rep(i, m) {
		int u, v; cin >> u >> v; u--, v--;
		g[u].pb(v), g[v].pb(u);
	}
	rep(i, n) dfs(i, -1, {a[i]});
	if(f) printf("YES\n");
	else printf("NO\n");
	return 0;
}