def isTrees(x1, x2, x3):
  if x1 != x3 and ((x2 > x1 and x2 > x3) or (x2 < x1 and x2 < x3)):
      return True
  else:
    return False

n,m = input().split(' ')
a = []
a = input().split(' ')
v = []
for i in range(0,int(m)):
  v.append(input().split(' '))

result = 'NO'

for i in range(0,int(m)):
  for j in range(i + 1, int(m)):
    if i != j:
      if v[i][0] in v[j]:
        t = 1 if(v[j].index(v[i][0]) == 0) else 0
        if isTrees(a[int(v[j][t])-1], a[int(v[i][0])-1], a[int(v[i][1])-1]):
          result = 'YES'
      if v[i][1] in v[j]:
        t = 1 if(v[j].index(v[i][1]) == 0) else 0
        if isTrees(a[int(v[j][t])-1], a[int(v[i][1])-1], a[int(v[i][0])-1]):
          result = 'YES'
  if result == 'YES':
    break

print(result)