import sys

n,d = map(int, sys.stdin.readline().split())
a = list(map(int, sys.stdin.readline().split()))
ls = [0]*n
ans = -1
for j in range(n):
    l = a[j]
    r = l+d
    cnt = 0
    for i in range(n):
        if a[i] < l: ls[i] = l
        elif a[i] > r: ls[i] = r
        else: ls[i] = a[i]
    for i in range(n-1):
        cnt += abs(ls[i]-ls[i+1])
    ans = max(cnt, ans)
for j in range(n):
    r = a[j]
    l = r-d
    cnt = 0
    for i in range(n):
        if a[i] < l: ls[i] = l
        elif a[i] > r: ls[i] = r
        else: ls[i] = a[i]
    for i in range(n-1):
        cnt += abs(ls[i]-ls[i+1])
    ans = max(cnt, ans)
print(ans)