from itertools import combinations

N, K = int(input()), int(input())
s = list(sorted([int(input()) for i in range(N)]))

ans = 0

for x in combinations(range(1, N), K - 1):
    mx, mn = 0, 10000000000
    x = [0] + list(x) + [N]
    for k in range(1, K + 1):
        print(x[k - 1], x[k])
        x1, x2 = x[k - 1], x[k]
        sss = sum(s[x1:x2]) / (x2 - x1)
        mx = max(sss, mx)
        mn = min(sss, mn)
    ans = max(ans, mx - mn)
print(int(ans) + (1 if int(ans) != ans else 0))