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

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

x = T



for i in range(1,N):

    if t[i]-t[i-1] >= T:

        x += T

    elif t[i]+T > T:

        x += t[i]-t[i-1]

print(x)

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

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

x = T



for i in range(1,N):

    if t[i]-t[i-1] >= T:

        x += T

    else:

        x += t[i]-t[i-1]

print(x)

N, T = list(map(int, input().split()))
t = list(map(int, input().split()))
x = T
for i in range(1, N):
    if t[i] - t[i - 1] >= T:
        x += T
    elif t[i] + T > T:
        x += t[i] - t[i - 1]
print(x)

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

-    elif t[i] + T > T: +    else: