import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
inf = 10**18
from functools import lru_cache
sys.setrecursionlimit(10**6)
@lru_cache(maxsize=None)
def saiki(a):
    if len(a) == 0:
        return 0
    #print(a)
    res = -inf
    for i in range(len(a)):
        if a[i] <= k:
            res = max(res, a[i]-saiki(a[:i] + a[i+1:]))
        else:
            for x in range(1, a[i]//2+1):
                res = max(res, -saiki(a[:i] +(x, a[i] - x)+ a[i+1:]))
    return res

def solve(a):
    f = sorted([x for x in a if x <= k])
    res = sum([y * [1, -1][j%2] for j, y in enumerate(f[::-1])])
    if len(f)%2:
        return res - solve2([x for x in a if x > k])
    else:
        return res + solve2([x for x in a if x > k])

def solve2(a):
    if len(a) % 2:
        return -(sum(a)%2)
    else:
        return sum(a)%2



n, k = na()
a = na()

print((solve(tuple(a))+sum(a))//2)
# k = 1
# from random import randint
# while True:
#     n = randint(1,5)
#     a = [randint(1,5) for i in range(n)]
#     A = solve(a)
#     B = saiki(tuple(a))
#     print(a)
#     if A != B:
#         print(a, A, B)