codeforces 1070/D

bags = 0
d = list(map(int, input().split()))
n = d[0]
k = d[1]
a = list(map(int, input().split()))
trashRn = a[0]


for i in range(1, n):
  trashRn += a[i]
  remain = trashRn % k
  bagsRn = trashRn // k
  bags += bagsRn
  trashRn %= k
  if bagsRn == 0 and remain != 0: # meaning its 1 day old for sure
    bags += 1
    trashRn = 0

if remain != 0 and bagsRn != 0:
  bags+=1

print(bags)