import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import itertools

N,M = map(int,readline().split())
A = [0] + list(map(int,readline().split()))
m = map(int,read().split())
UV = zip(m,m)

find = False
for (u1,v1),(u2,v2) in itertools.combinations(UV,2):
    if u1 == u2:
        a,b,c = v1,u1,v2
    elif u1 == v2:
        a,b,c = v1,u1,u2
    elif v1 == u2:
        a,b,c = u1,v1,v2
    elif v1 == v2:
        a,b,c = u1,v1,u2
    else:
        continue
    a,b,c = A[a], A[b], A[c]
    if a == c:
        continue
    if a > b < c or a < b > c:
        find = True
        break

answer = 'YES' if find else 'NO'
print(answer)