#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;

int b = 0;

struct Graph {
    struct Vertex { int n, a; };
    struct Edge { int i, n; };
    Graph(int n, int m) : v(n, { -1 }), e(m), n(n), m(0) {}
    void add_edge(int i, int j) {
        e[m] = { j, v[i].n };
        v[i].n = m;
        m++;
    }
    void foo() {
        for (int i = 0; i < n; i++) {
            int m0, m1;
            m0 = m1 = 0;
            int a = v[i].a;
            for (int j = v[i].n; j >= 0; j = e[j].n) {
                Edge& o = e[j];
                int m = v[o.i].a;
                if (m < a) {
                    if (m0 == 0) {
                        m0 = m;
                    } else {
                        if (m != m0) b = 1;
                    }
                } else if (m > a) {
                    if (m1 == 0) {
                        m1 = m;
                    } else {
                        if (m != m1) b = 1;
                    }
                }
            }
        }
    }
    vector<Vertex> v;
    vector<Edge> e;
    int n, m;
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, m;
    cin >> n >> m;

    Graph g(n, m * 2);
    for (int i = 0; i < n; i++) {
        cin >> g.v[i].a;
    }
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--; v--;

        g.add_edge(u, v);
        g.add_edge(v, u);
    }

    g.foo();

    cout << (b ? "YES" : "NO") << endl;

    return 0;
}