mod = 10 ** 9 + 7
mod2 = 2**61+1
from collections import deque
import heapq
from bisect import bisect_left, insort_left, bisect_right

def iip(listed=True):
    ret = [int(i) for i in input().split()]
    if len(ret) == 1 and not listed:
        return ret[0]
    return ret

def iip_ord():
    return [ord(i) - ord("a") for i in input()]


def main():
    ans = solve()
    if ans is not None:
        print(ans)

def solve():
    N, K = iip(False)
    X = iip()

    A1 = [i for i in X if i >= 0]
    A2 = [-i for i in X if i < 0]
    A2.sort()

    ans = 10**50
    if len(A1) >= K:
        ans = A1[K-1]
    if len(A2) >= K:
        ans = min(A2[K-1])

    for i in range(1, len(A1)):
        i1 = i-1
        i2 = K-i-1
        if i1 >= len(A1):
            break
        if i2 >= len(A2):
            break
        ans = min(2*A1[i1]+A2[i2], ans)
        ans = min(2*A2[i2]+A1[i1], ans)

    print(ans)


#####################################################ライブラリ集ここから

def YesNo(s):
    if s:
        print("Yes")
    else:
        print("No")


def fprint(s):
    for i in s:
        print(i)

def split_print_space(s):
    print(" ".join([str(i) for i in s]))


def split_print_enter(s):
    print("\n".join([str(i) for i in s]))


def koenai_saidai_x_index(sorted_list, n):
    l = 0
    r = len(sorted_list)
    if len(sorted_list) == 0:
        return False
    if sorted_list[0] > n:
        return False

    while r - l > 1:
        x = (l + r) // 2
        if sorted_list[x] == n:
            return x
        elif sorted_list[x] > n:
            r = x
        else:
            l = x
    return l


def searchsorted(sorted_list, n, side):
    if side not in ["right", "left"]:
        raise Exception("sideはrightかleftで指定してください")

    l = 0
    r = len(sorted_list)

    if n > sorted_list[-1]:
        # print(sorted_list)
        return len(sorted_list)
    if n < sorted_list[0]:
        return 0

    while r - l > 1:
        x = (l + r) // 2
        if sorted_list[x] > n:
            r = x
        elif sorted_list[x] < n:
            l = x
        else:
            if side == "left":
                r = x
            elif side == "right":
                l = x

    if side == "left":
        if sorted_list[l] == n:
            return r - 1
        else:
            return r

    if side == "right":
        if sorted_list[l] == n:
            return l + 1
        else:
            return l


def soinsuu_bunkai(n):
    ret = []
    for i in range(2, int(n ** 0.5) + 1):
        while n % i == 0:
            n //= i
            ret.append(i)
        if i > n:
            break
    if n != 1:
        ret.append(n)
    return ret


def conbination(n, r, mod, test=False):
    if n <= 0:
        return 0
    if r == 0:
        return 1
    if r < 0:
        return 0
    if r == 1:
        return n
    ret = 1
    for i in range(n - r + 1, n + 1):
        ret *= i
        ret = ret % mod

    bunbo = 1
    for i in range(1, r + 1):
        bunbo *= i
        bunbo = bunbo % mod

    ret = (ret * inv(bunbo, mod)) % mod
    if test:
        # print(f"{n}C{r} = {ret}")
        pass
    return ret


def inv(n, mod):
    return power(n, mod - 2)


def power(n, p, mod_= mod):
    if p == 0:
        return 1
    if p % 2 == 0:
        return (power(n, p // 2, mod_) ** 2) % mod_
    if p % 2 == 1:
        return (n * power(n, p - 1, mod_)) % mod_


if __name__ == "__main__":
    main()

### FIXED CODE ###

mod = 10 ** 9 + 7
mod2 = 2**61+1
from collections import deque
import heapq
from bisect import bisect_left, insort_left, bisect_right

def iip(listed=True):
    ret = [int(i) for i in input().split()]
    if len(ret) == 1 and not listed:
        return ret[0]
    return ret

def iip_ord():
    return [ord(i) - ord("a") for i in input()]


def main():
    ans = solve()
    if ans is not None:
        print(ans)

def solve():
    N, K = iip(False)
    X = iip()

    A1 = [i for i in X if i > 0]
    A2 = [-i for i in X if i < 0]
    A2.sort()
    if 0 in X:
        K -= 1
        if K == 0:
            return 0

    ans = 10**50

    if K == 1:
        return min(A1[0], A2[0])

    for i in range(N):
        i1 = i-1
        i2 = K-i-1

        #print(i1, i2, len(A1), len(A2))
        #print(A1, A2)
        if i1 < -1 or i2 < -1 or i1 >= len(A1) or i2 >= len(A2):
            continue

        if i1 == -1:
            a = 0
        else:
            a = A1[i1]

        if i2 == -1:
            b = 0
        else:
            b = A2[i2]

        ans = min(ans, a*2+b, b*2+a)

    try:
        ans = min(A1[K-1], ans)
    except:
        pass

    try:
        ans = min(A2[K-1], ans)
    except:
        pass

    #print(A1)
    #print(A2)
    print(ans)


#####################################################ライブラリ集ここから

def YesNo(s):
    if s:
        print("Yes")
    else:
        print("No")


def fprint(s):
    for i in s:
        print(i)

def split_print_space(s):
    print(" ".join([str(i) for i in s]))


def split_print_enter(s):
    print("\n".join([str(i) for i in s]))


def koenai_saidai_x_index(sorted_list, n):
    l = 0
    r = len(sorted_list)
    if len(sorted_list) == 0:
        return False
    if sorted_list[0] > n:
        return False

    while r - l > 1:
        x = (l + r) // 2
        if sorted_list[x] == n:
            return x
        elif sorted_list[x] > n:
            r = x
        else:
            l = x
    return l


def searchsorted(sorted_list, n, side):
    if side not in ["right", "left"]:
        raise Exception("sideはrightかleftで指定してください")

    l = 0
    r = len(sorted_list)

    if n > sorted_list[-1]:
        # print(sorted_list)
        return len(sorted_list)
    if n < sorted_list[0]:
        return 0

    while r - l > 1:
        x = (l + r) // 2
        if sorted_list[x] > n:
            r = x
        elif sorted_list[x] < n:
            l = x
        else:
            if side == "left":
                r = x
            elif side == "right":
                l = x

    if side == "left":
        if sorted_list[l] == n:
            return r - 1
        else:
            return r

    if side == "right":
        if sorted_list[l] == n:
            return l + 1
        else:
            return l


def soinsuu_bunkai(n):
    ret = []
    for i in range(2, int(n ** 0.5) + 1):
        while n % i == 0:
            n //= i
            ret.append(i)
        if i > n:
            break
    if n != 1:
        ret.append(n)
    return ret


def conbination(n, r, mod, test=False):
    if n <= 0:
        return 0
    if r == 0:
        return 1
    if r < 0:
        return 0
    if r == 1:
        return n
    ret = 1
    for i in range(n - r + 1, n + 1):
        ret *= i
        ret = ret % mod

    bunbo = 1
    for i in range(1, r + 1):
        bunbo *= i
        bunbo = bunbo % mod

    ret = (ret * inv(bunbo, mod)) % mod
    if test:
        # print(f"{n}C{r} = {ret}")
        pass
    return ret


def inv(n, mod):
    return power(n, mod - 2)


def power(n, p, mod_= mod):
    if p == 0:
        return 1
    if p % 2 == 0:
        return (power(n, p // 2, mod_) ** 2) % mod_
    if p % 2 == 1:
        return (n * power(n, p - 1, mod_)) % mod_


if __name__ == "__main__":
    main()