#!/usr/bin/env python3

import itertools


def has_kadomatsu_path(n, xs, adj_list):
    for v2 in range(n):
        for v1, v3 in itertools.combinations(adj_list[v2], 2):
            x1, x2, x3 = xs[v1], xs[v2], xs[v3]
            if x1 == x2 or x2 == x3 or x3 == x1:
                continue
            elif x2 == max(x1, x2, x3) or x2 == min(x1, x2, x3):
                return True
    else:
        return False


def main():
    n, m = (int(x) for x in input().split())
    xs = [int(x) for x in input().split()]
    adj_list = [set() for _ in range(n)]
    for _ in range(m):
        u, v = (int(z) - 1 for z in input().split())
        adj_list[u].add(v)
        adj_list[v].add(u)
    print("YES" if has_kadomatsu_path(n, xs, adj_list) else "NO")


if __name__ == '__main__':
    main()