N,M = map(int,input().split())
A =[0]+list(map(int,input().split()))
G = {i:[] for i in range(1,N+1)}
for _ in range(M):
    u,v = map(int,input().split())
    G[u].append(v)
    G[v].append(u)
ans = "NO"
for i in range(1,N+1):
    if len(G[i])<2:continue
    for j1 in range(len(G[i])-1):
        for j2 in range(j1+1,len(G[i])):
            u = G[i][j1]
            v = G[i][j2]
            if A[i]!=A[u] and A[u]!=A[v] and A[v]!=A[i] and (max(A[i],A[u],A[v])==A[i] or min(A[i],A[u],A[v])==A[i]):
                ans = "YES"
                break
        if ans=="YES":break
    if ans=="YES":break
print(ans)