#!/usr/bin/env pypy3

import sys


REC_LIMIT = 10000


# http://www.prefield.com/algorithm/sort/mergecount.html
def inversion_number(xs):
    n = len(xs)
    cnt = 0
    if n > 1:
        bs = xs[:n // 2]
        cs = xs[n // 2:]
        cnt += inversion_number(bs)
        cnt += inversion_number(cs)
        j = 0
        k = 0
        for i in range(n):
            if k == len(cs):
                xs[i] = bs[j]
                j += 1
            elif j == len(bs):
                xs[i] = cs[k]
                k += 1
            elif bs[j] <= cs[k]:
                xs[i] = bs[j]
                j += 1
            else:
                xs[i] = cs[k]
                k += 1
                cnt += n // 2 - j
    return cnt


def judge(n, k, ds):
    inv_n = inversion_number(ds)
    return inv_n <= k and (inv_n + k) % 2 == 0


def main():
    sys.setrecursionlimit(REC_LIMIT)
    n, k = (int(x) for x in input().split())
    ds = [int(x) for x in input().split()]
    print("YES" if judge(n, k, ds) else "NO")


if __name__ == '__main__':
    main()