N,K = map(int,input().split())
D = list(map(int,input().split()))
m = 0
while 2**m<N:
    m += 1
M = 2**m
T = [0]*(M+1)
def plus(i,x):
    j = i
    while j<=M:
        T[j] += x
        j += j&(-j)
def cumsum(i):
    cnt = 0
    j = i
    while j>0:
        cnt += T[j]
        j -= j&(-j)
    return cnt
tot = 0
for i in range(N):
    k = D[i]
    tot += i-cumsum(k)
    plus(k,1)
if tot>K:
    print("NO")
elif (K-tot)%2==0:
    print("YES")
else:
    print("NO")