from collections import deque
N, M = map(int, input().split())
a = tuple(map(int, input().split()))
vertices = [[] for _ in [0]*N]
for _ in [0]*M:
    u, v = map(int, input().split())
    vertices[u-1].append(v-1)
    vertices[v-1].append(u-1)

for i in range(N):
    i_value = a[i]
    for j in vertices[i]:
        j_value = a[j]
        if i_value == j_value:
            continue
        for k in vertices[j]:
            if i == k or i_value == a[k]:
                continue
            if (i_value-j_value) * (a[k]-j_value) > 0:
                print("YES")
                exit()
print("NO")