import java.io.*;
import java.util.*;


class Main {
    static ArrayList<Integer>[]g;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));
        int n=sc.nextInt();
        int m=sc.nextInt();
        int[]a=sc.nextIntArray(n);
        g=new ArrayList[n];
        Arrays.setAll(g,x->new ArrayList<Integer>());
        for(int i=0;i<m;++i){
            int u=sc.nextInt()-1;
            int v=sc.nextInt()-1;
            g[u].add(v);
            g[v].add(u);
        }
        for(int i=0;i<n;++i){
            int s=g[i].size();
            for(int j=0;j<s;++j){
                int u=g[i].get(j);
                for(int k=0;k<j;++k){
                    int v=g[i].get(k);
                    if(a[u]!=a[v]&&(a[u]-a[i])*(a[v]-a[i])>0){
                        out.println("YES");
                        out.close();
                        return;
                    }
                }
            }
        }
        out.println("NO");
        out.close();
    }
    // http://codeforces.com/blog/entry/7018
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;
        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        int[] nextIntArray(int n){
            int[]r=new int[n];
            for(int i=0;i<n;++i)r[i]=nextInt();
            return r;
        }
    }
}