n, k = map(int, input().split())
A = list(map(int, input().split()))
A.sort(reverse=True)
all_ = sum(A)
ans = 0
t = 0
for a in A:
    if a > k:
        continue
    if t == 0:
        ans += a
    else:
        ans -= a
    t ^= 1

c = len([a for a in A if a >= k and a % 2 == 1])
if t == 0:
    ans += 1 - c & 1

print((all_ + ans) // 2)