def kadomatsu(a,b,c):
    if (min(a,b,c)==b or max(a,b,c)==b) and a!=b and b!=c and c!=a:
        return True
    else:
        return False
n,m=map(int,input().split())
a=[0]+list(map(int,input().split()))
g=[[] for _ in range(n+1)]
for _ in range(m):
    x,y=map(int,input().split())
    g[x].append(y)
    g[y].append(x)
f=False
for p in range(1,n+1):
    if len(g[p])<2:
        continue
    for i in range(len(g[p])):
        for j in range(i+1,len(g[p])):
            if kadomatsu(a[g[p][i]],a[p],a[g[p][j]]):
                f=True
                break
print('YES' if f else 'NO')