N,T = list(map(int,input().split()))

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

ov = 0

for i in range(N-1):

    if (order[i+1]-order[i])<T:

        ov += T-(order[i+1]-order[i])

print((N*T-ov))
N,T = list(map(int,input().split()))

last, time = 0,-T

for temp in map(int,input().split()):

    if temp - last < T:

        time += T - (temp - last)

    last = temp

print((N*T-time))
N, T = list(map(int, input().split()))
order = list(map(int, input().split()))
ov = 0
for i in range(N - 1):
    if (order[i + 1] - order[i]) < T:
        ov += T - (order[i + 1] - order[i])
print((N * T - ov))

N, T = list(map(int, input().split()))
last, time = 0, -T
for temp in map(int, input().split()):
    if temp - last < T:
        time += T - (temp - last)
    last = temp
print((N * T - time))

-order = list(map(int, input().split())) -ov = 0 -for i in range(N - 1): -    if (order[i + 1] - order[i]) < T: -        ov += T - (order[i + 1] - order[i]) -print((N * T - ov)) +last, time = 0, -T +for temp in map(int, input().split()): +    if temp - last < T: +        time += T - (temp - last) +    last = temp +print((N * T - time))