n, t = list(map(int, input().split()))

tList = list(map(int, input().split()))

tSum = t



for i in range(n-1):

    if tList[i+1] - tList[i] > t:

        tSum += t

    else:

        tSum += tList[i+1] - tList[i]



print(tSum)

n, t = list(map(int, input().split()))

tList = list(map(int, input().split()))

tSum = t



for i in range(n-1):

    tElapse = tList[i+1] - tList[i]

    tSum += (t if tElapse > t else tElapse)



print(tSum)

n, t = list(map(int, input().split()))
tList = list(map(int, input().split()))
tSum = t
for i in range(n - 1):
    if tList[i + 1] - tList[i] > t:
        tSum += t
    else:
        tSum += tList[i + 1] - tList[i]
print(tSum)

n, t = list(map(int, input().split()))
tList = list(map(int, input().split()))
tSum = t
for i in range(n - 1):
    tElapse = tList[i + 1] - tList[i]
    tSum += t if tElapse > t else tElapse
print(tSum)

-    if tList[i + 1] - tList[i] > t: -        tSum += t -    else: -        tSum += tList[i + 1] - tList[i] +    tElapse = tList[i + 1] - tList[i] +    tSum += t if tElapse > t else tElapse