#!/usr/bin/env python3
(n, k), xs, ans = map(int, input().split()), list(map(int, input().split())), 0
while not all(a <= b for a, b in zip(xs[:-1], xs[1:])):
    for i in range(n - k + 1): xs[i:i + k] = sorted(xs[i:i + k])
    ans += 1
print(ans)