/* -*- coding: utf-8 -*-
 *
 * 629.cc: No.629 グラフの中に眠る門松列 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 1000;

/* typedef */

typedef vector<int> vi;

/* global variables */

int as[MAX_N];
vi nbrs[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < n; i++) scanf("%d", &as[i]);

  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    u--, v--;
    nbrs[u].push_back(v);
    nbrs[v].push_back(u);
  }

  for (int i = 0; i < n; i++) {
    vi &nbr0 = nbrs[i];
    for (vi::iterator vit0 = nbr0.begin(); vit0 != nbr0.end(); vit0++) {
      int &j = *vit0;
      if (as[i] == as[j]) continue;

      vi &nbr1 = nbrs[j];
      for (vi::iterator vit1 = nbr1.begin(); vit1 != nbr1.end(); vit1++) {
	int &k = *vit1;
	if (as[i] != as[k] &&
	    ((as[j] < as[i] && as[j] < as[k]) ||
	     (as[j] > as[i] && as[j] > as[k]))) {
	  puts("YES");
	  return 0;
	}
      }      
    }
  }

  puts("NO");
  return 0;
}