#!/usr/bin/env python3

n, k = map(int, input().split())
a = list(map(int, input().split()))

l = 0
while True:
    issorted = True
    for i in range(n - 1):
        if a[i] > a[i + 1]:
            issorted = False
    if issorted:
        break
    l += 1
    for i in range(0, n - k + 1):
        a[i : i + k] = sorted(a[i : i + k])

print(l)