import sys

N, M = map(int, input().split())
l = list(map(int, input().split())) 
conect_l = [[] for i in range(N)]

for i in range(M):
    node1, node2 = map(int, input().split())
    conect_l[node1 - 1].append(l[node1 - 1] - l[node2 - 1])
    conect_l[node2 - 1].append(l[node2 - 1] - l[node1 - 1])

for i in range(M):
    s = set(conect_l[i])
    ck = list(s)
    posi_n = 0
    nega_n = 0
    for l_i in ck:
        if l_i > 0:
            posi_n += 1
        if l_i < 0:
            nega_n += 1
    if posi_n >= 2:
        print("YES")
        sys.exit()
    if nega_n >= 2:
        print("YES")
        sys.exit()

print("NO")