1.1 KB | 1131 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
SYS_INPUT = False
RECURSION_LIMIT = 10 ** 7
SET_RECURSION = False
BLANK = " "
if SET_RECURSION:
sys.setrecursionlimit(RECURSION_LIMIT)
inp = lambda : sys.stdin.readline().rstrip() if SYS_INPUT else input()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
isplit = lambda : inp().split()
p = print
def gcd(a, b): return gcd(b, a % b) if b > 0 else a
def lcm(a, b): return a * b // gcd(a, b)
def f(l, k):
n = len(l)
l.sort(reverse=True)
ans = 0
mx = 0
for i in range(n):
mx = max(mx, l[i])
if (i + 1) % k == 0:
ans += mx * 2
mx = 0
ans += mx * 2
return ans
def solve():
n, k = mii()
ar = [ii() for _ in range(n)]
minus = [-i for i in ar if i < 0]
plus = [i for i in ar if i > 0]
ans = f(minus, k) + f(plus, k)
p(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()