n,k,l,u=map(int,input().split())
mid=(l+u)//2
A=[int(_) for _ in input().split()]
avg=sum(A)//n
un_nature=0
for i in range(n):
    tmp=A[i]+mid-avg
    if tmp<l:
        un_nature+=(l-tmp+k-1)//k
    elif tmp>u:
        un_nature+=(tmp-u+k-1)//k
print(un_nature)