# input
import sys
input = sys.stdin.readline
II = lambda : int(input())
MI = lambda : map(int, input().split())
LI = lambda : [int(a) for a in input().split()]
SI = lambda : input().rstrip()
LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)]
LSI = lambda n : [input().rstrip() for _ in range(n)]
MI_1 = lambda : map(lambda x:int(x)-1, input().split())
LI_1 = lambda : [int(a)-1 for a in input().split()]

mod = 998244353
inf = 1001001001001001001
ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97
ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97
yes = lambda : print("Yes")
no = lambda : print("No")
yn = lambda flag : print("Yes" if flag else "No")

prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1)
alplow = "abcdefghijklmnopqrstuvwxyz"
alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)}
DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]]
DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]]
DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]]
prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59]
sys.set_int_max_str_digits(0)
# sys.setrecursionlimit(10**6)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')

from collections import defaultdict,deque
from heapq import heappop,heappush
from bisect import bisect_left,bisect_right
DD = defaultdict
BSL = bisect_left
BSR = bisect_right

class DSU:
    n : int 
    par : list[int]
    siz : list[int]
    fix_leader : bool
    __slots__ = ["n", "par", "siz", "fix_leader"]
    
    def __init__(self, n, fix_leader = False):
        self.n = n
        self.par = [*range(n)]
        self.siz = [1] * n
        self.fix_leader = fix_leader

    def leader(self, a):
        while self.par[a] != a:
            a = self.par[self.par[a]]
            self.par[a] = self.par[self.par[a]]
        return a

    def merge(self, a, b):
        a = self.leader(a)
        b = self.leader(b)
        if a == b: return a
        if self.fix_leader or self.siz[a] > self.siz[b]:
            self.siz[a] += self.siz[b]
            self.par[b] = a
            return a
        else:
            self.siz[b] += self.siz[a]
            self.par[a] = b
            return b

    def same(self, a, b):
        return self.leader(a) == self.leader(b)
    
    def size(self, a):
        return self.siz[self.leader(a)]
    
    def groups(self):
        res = [[] for i in range(self.n)]
        for i in range(self.n):
            res[self.leader(i)].append(i)
        res2 = []
        for i in range(self.n):
            if len(res[i]) > 0:
                res2.append(res[i])
        return res2

def Cartesian_Tree(a):
    n = len(a)
    par = [-1] * n
    st = []
    for i, v in enumerate(a):
        s = -1
        while st and a[st[-1]] > v:
            s = st.pop()
        if s != -1:
            par[s] = i
        if st:
            par[i] = st[-1]
        st.append(i)

    left = [-1] * n
    right = [-1] * n
    for i, p in enumerate(par):
        if p == -1:
            continue
        if i < p:
            left[p] = i
        else:
            right[p] = i
    return par, left, right


n, k = MI()
a = LI()


p, l, r = Cartesian_Tree(a)
root = p.index(-1)

order = [root]
for v in order:
    if l[v] != -1:
        order.append(l[v])
    if r[v] != -1:
        order.append(r[v])

# 一度に消すおおきさ
s = [1] * n
for v in order[::-1]:
    if l[v] != -1:
        s[v] += s[l[v]]
    if r[v] != -1:
        s[v] += s[r[v]]

# コストごとの
c = [0] * (n + 1)
for v in range(n):
    if p[v] == -1:
        c[s[v]] += a[v]
    else:
        c[s[v]] += a[v] - a[p[v]] 

ans = a[0] + a[-1]
for i in range(n-1):
    ans += abs(a[i] - a[i+1])

for s in range(1, n+1):
    x = min(c[s], k // s)
    k -= x * s
    ans -= 2 * x

print(ans)