from bisect import bisect_right

N,K,L,U = map(int,input().split())
A = list(map(int,input().split()))
A.sort()
now_li = 0
now_ui = bisect_right(A,U-L+A[0]) - 1
now_l = A[0]

if now_ui == N-1:
    print(0)
else:
    count = -1
    now_llist = []
    while now_ui < N-1:
        now_llist.append(now_l)
        if A[now_ui+1] - (now_l + U - L) < A[now_li+1] - now_l:
            now_l = A[now_ui+1] - U + L
            now_ui += 1
        else:
            now_l = A[now_li]
            now_li += 1
        if N - 1 - now_ui <= now_li:
            count = len(now_llist)
    if count==-1:
        count = len(now_llist)
    max_ans = 10**10
    for now_l in now_llist[max(count-5,0):min(count+5,len(now_llist))]:
        now_u = now_l + U - L
        ans = 0
        k_list1 = [0]*K
        k_list2 = [0]*K
        for a in A:
            ans += max(now_l - a + K - 1, 0)//K
            if a < now_l:
                k_list1[a%K]+=1
            ans += max(a - now_u + K - 1, 0)//K
            if now_u - K < a:
                k_list2[a%K]+=1
        max_ans = min(ans, max_ans)
        for i in range(1,K-1):
            ans -= k_list1[(now_l-i)%K]
            ans += k_list2[(now_u-i+1)%K]
            max_ans = min(ans, max_ans)
        k_list1 = [0]*K
        k_list2 = [0]*K
        for a in A:
            ans += max(now_l - a + K - 1, 0)//K
            if a < now_l + K:
                k_list1[a%K]+=1
            ans += max(a - now_u + K - 1, 0)//K
            if now_u < a:
                k_list2[a%K]+=1
        for i in range(1,K-1):
            ans += k_list1[(now_l+i-1)%K]
            ans -= k_list2[(now_u+i)%K]
            max_ans = min(ans, max_ans)

    print(max_ans)