n, k, L, U = map(int, input().split())
A = list(map(int, input().split()))
l = -(1 << 60)
r = 1 << 60
while r - l > 1:
    mid = (l + r) // 2
    c = 0
    for a in A:
        x = a + mid
        if x < L:
            c += 1
        elif x + k >= U:
            c -= 1
    if c > 0:
        l = mid
    else:
        r = mid

A = [a + l for a in A]
tot = 0
add = {}
for a in A:
    if a < L:
        tot += (L - a + k - 1) // k
        x = (L - a) % k
        if x == 0:
            x = k
        add[x] = add.get(x, 0) - 1
    elif a + k > U:
        tot += (a - U + k - 1) // k
        x = (U - a + 1) % k
        if x == 0:
            x = k
        add[x] = add.get(x, 0) + 1

ans = tot
for k in sorted(add.keys()):
    tot += add[k]
    ans = min(ans, tot)
print(ans)