def v(s):
    if len(s) < 2:
        return 0
    return int(s[-1]) - int(s[0])

def va2(l, i):
    v1 = l[i-1] - l[0]
    v2 = l[-1] - l[i]
    return v1 + v2

def groupSplit(group):
    mini = 1
    minv = va2(group, 1)

    for i in range(2, len(group)):
        tminv = va2(group, i)
        if tminv < minv:
            minv = tminv
            mini = i

    return group[:mini], v(group[:mini]), \
           group[mini:], v(group[mini:]),

def solve(l, k, d):
    if l == k:
        return 0
    d.sort(key=int)
    groups = [tuple([int(k) for k in d])]
    for _ in range(0, k - 1):
        mini = 0
        group1, v1, group2, v2 = groupSplit(groups[mini])
        maxdiff = (v1 + v2) - v(list(groups[mini]))
        for i, g in enumerate(groups[1:], start=1):
            if v(g) < maxdiff:
                continue
            tgroup1, tv1, tgroup2, tv2 = groupSplit(list(g))
            tmindiff = (tv1 + tv2) - v(list(g))
            if tmindiff < maxdiff:
                mini = i
                group1 = tgroup1
                group2 = tgroup2
                v1, v2 = tv1, tv2
                maxdiff = tmindiff
        del groups[mini]
        groups.append(tuple(sorted(group1)))
        groups.append(tuple(sorted(group2)))
    return sum([v(s) for s in groups])

if __name__ == '__main__':
    l, k = map(int, input().split())
    print(solve(l, k, input().split()))