import sys, random
input = lambda : sys.stdin.readline().rstrip()

write = lambda x: sys.stdout.write(x+"\n"); writef = lambda x: print("{:.12f}".format(x))
debug = lambda x: sys.stderr.write(x+"\n")
YES="Yes"; NO="No"; pans = lambda v: print(YES if v else NO); inf=10**18
LI = lambda : list(map(int, input().split()))
def debug(_l_):
    for s in _l_.split():
        print(f"{s}={eval(s)}", end=" ")
    print()
def dlist(*l, fill=0):
    if len(l)==1:
        return [fill]*l[0]
    ll = l[1:]
    return [dlist(*ll, fill=fill) for _ in range(l[0])]
sys.setrecursionlimit(3*10**5+10)

n,k,x,y = list(map(int, input().split()))
dp = [[-inf]*k for _ in range(k)]
x %= k
y %= k
dp[x][y] = dp[y][x] = 0
a = LI()
xs = [-inf]*k
ys = [-inf]*k
xs[x] = ys[y] = xs[y] = ys[x] = 0
for i in range(n):
    v0 = a[i]%k
    v = (-a[i]) % k
    for xx in range(k):
        yy = (v - xx) % k
        if dp[xx][yy]==-inf:
            continue
#         print(v, xx, yy)
        dp[xx][yy] += 1
        xs[xx] = max(xs[xx], dp[xx][yy])
        ys[yy] = max(ys[yy], dp[xx][yy])
    nxs = xs[:]
    nys = ys[:]
    for xx in range(k):
        dp[xx][v0] = max(dp[xx][v0], ys[xx])
        dp[v0][xx] = max(dp[v0][xx], xs[xx])
        nxs[xx] = max(nxs[xx], dp[xx][v0])
        nys[xx] = max(nys[xx], dp[v0][xx])
        nxs[v0] = max(nxs[v0], dp[v0][xx])
        nys[v0] = max(nys[v0], dp[xx][v0])
    xs = nxs
    ys = nys
#     break
ans = -inf
for item in dp:
    ans = max(ans, max(item))
print(ans)