#!/usr/bin/env python3
n,k = [int(i) for i in input().split()]
a = [int(i) for i in input().split()]

t = 0
while True:
    t += 1
    for i in range(n-k+1):
        a[i:i+k] = sorted(a[i:i+k])
    if a == sorted(a):
        break
print(t)