import sys
import math
sys.setrecursionlimit(10**7)
class lazysegki():
    #区間和のセグメント木、葉の数N,要素ls
    def __init__(self,N,ls,mode='sum'): 
        self.default = 0
        self.func = (lambda x, y: x + y)
        self.N = N
        self.K = (N-1).bit_length()
        self.N0 = 1 << self.K 
        self.dat = [self.default]*(2**(self.K+1)) #全体の配列を用意(maxなら-inf,minなら+infで未構築を表現)　
        self.lazy = [0]*(2**(self.K+1)) #遅延評価
        for i in range(self.N): #葉の構築
            self.dat[2**self.K+i] = ls[i]
        self.build()

    def build(self):
        for j in range(self.N0-1,0,-1):
            self.dat[j] = self.func(self.dat[j<<1],self.dat[j<<1|1]) #親が持つ条件

    def leafvalue(self,x): #x番目の値を出力
        return self.query(x,x+1)

    def update_add(self,x,y): #x番目にyを足す
        return self.updatel_add(x,x+1,y)

    def gindex(self,l, r): #伝播するインデックス列挙
        L = l + self.N0; R = r + self.N0
        lm = (L // (L & -L)) >> 1
        rm = (R // (R & -R)) >> 1
        lsindex = []
        while L < R:
            if R <= rm:
                lsindex.append(R)
            if L <= lm:
                lsindex.append(L)
            L >>= 1; R >>= 1
        while L:
            lsindex.append(L)
            L >>= 1
        return lsindex

    def propagates(self,ids):
        for i in reversed(ids):
            v = self.lazy[i]
            if not v:
                continue
            self.lazy[i<<1] += v//2; self.lazy[i<<1|1] += v//2
            self.dat[i<<1] += v//2; self.dat[i<<1|1] += v//2
            self.lazy[i] = 0

    def updatel_add(self,l, r, x):#区間にyを足す
        self.propagates(self.gindex(l, r))
        L = self.N0 + l
        R = self.N0 + r
        ii = 0
        while L < R:
            if L & 1:
                self.lazy[L] += x*(2**ii)
                self.dat[L] += x*(2**ii)
                L += 1
            if R & 1:
                R -= 1
                self.lazy[R] += x*(2**ii)
                self.dat[R] += x*(2**ii)
            L >>= 1
            R >>= 1
            ii += 1
        for i in self.gindex(l, r):
            self.dat[i] = self.func(self.dat[i<<1],self.dat[i<<1|1])+self.lazy[i]

    def query(self,l, r):
        self.propagates(self.gindex(l, r))
        L = self.N0 + l
        R = self.N0 + r
        vL = self.default
        vR = self.default
        while L < R:
            if L & 1:
                vL = self.func(vL,self.dat[L])
                L += 1
            if R & 1:
                R -= 1
                vR = self.func(self.dat[R],vR)
            L >>= 1
            R >>= 1
        return self.func(vL,vR)
N,K = map(int,input().split())
lsA = list(map(int,input().split()))
minA = min(lsA)
lsA2 = [i-minA for i in lsA]
lsv = [0]*(N)
lsv[0] = sum(lsA2)
lsc = [0]
c = 0
for i in range(1,N):
    lsv[i] = lsv[i-1]+(lsA2[i]-c)*(2*i-N)
    lsc.append(lsA2[i]-c)
    c += lsA2[i]-c
if K == 0:
    print(-max(lsv))
    exit()
SG = lazysegki(N,lsA2)
l = 0
r = K
lsq = [sum(lsA2[:K])]
for i in range(1,N):
    SG.updatel_add(0,i,lsc[i])
    SG.updatel_add(i,N,-lsc[i])
    while r < N and SG.leafvalue(l) > SG.leafvalue(r):
        l += 1
        r += 1
    lsq.append(SG.query(l,r))
lsans = []
for i in range(N):
    m = -(lsv[i]-lsq[i])
    m += lsq[i]
    lsans.append(m)
print(min(lsans))