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

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



p = 0

ans = 0

for time in times:

    start = min(p, time)

    ans += t - max(0, p - time)

    p = time + t

print(ans)

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

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

ans = 0

t = 0

for time in times:

    if time >= t:

        ans += T

        t = time + T

    else:

        diff = t - time

        ans += T - diff

        t = time + T

print(ans)
n, t = list(map(int, input().split()))
times = list(map(int, input().split()))
p = 0
ans = 0
for time in times:
    start = min(p, time)
    ans += t - max(0, p - time)
    p = time + t
print(ans)

N, T = list(map(int, input().split()))
times = list(map(int, input().split()))
ans = 0
t = 0
for time in times:
    if time >= t:
        ans += T
        t = time + T
    else:
        diff = t - time
        ans += T - diff
        t = time + T
print(ans)

-n, t = list(map(int, input().split())) +N, T = list(map(int, input().split())) -p = 0 +t = 0 -    start = min(p, time) -    ans += t - max(0, p - time) -    p = time + t +    if time >= t: +        ans += T +        t = time + T +    else: +        diff = t - time +        ans += T - diff +        t = time + T