from itertools import combinations

N,M=map(int,input().split())
A=[0]+list(map(int,input().split()))

Up  =[[] for _ in range(N+1)]
Down=[[] for _ in range(N+1)]

for _ in range(M):
    u,v=map(int,input().split())
    if A[u]>A[v]:
        Up[v].append(u)
        Down[u].append(v)
    elif A[u]<A[v]:
        Up[u].append(v)
        Down[v].append(u)

F=0
for i in range(1,N+1):
    for p,q in combinations(Up[i],r=2):
        if A[p]!=A[q]:
            F=1

    for p,q in combinations(Down[i],r=2):
        if A[p]!=A[q]:
            F=1

print("YES" if F else "NO")