n,k,x,y = map(int,input().split())
*a, = map(int,input().split())
x %= k
y %= k
dp = [[-10000]*k for _ in range(k)]
r = [-10000]*k
dp[x][y] = dp[y][x] = 0
r[x] = r[y] = 0
for ai in a:
    ai %= k
    for i in range(k):
        j = (-i-ai)%k
        dp[i][j] += 1
        r[i] = max(r[i],dp[i][j])
    nr = r[:]
    for i in range(k):
        dp[i][ai] = max(dp[i][ai], r[i])
        dp[ai][i] = max(dp[ai][i], r[i])
        nr[ai] = max(nr[ai],dp[i][ai])
    r = nr
    
print(max(max(dpi for dpi in dp)))