import sys
from collections import defaultdict, Counter, deque
from itertools import permutations, combinations, product, combinations_with_replacement, groupby, accumulate
import operator
from math import sqrt, gcd, factorial
# from math import isqrt, prod,comb  # python3.8用(notpypy)
#from bisect import bisect_left,bisect_right
#from functools import lru_cache,reduce
#from heapq import heappush,heappop,heapify,heappushpop,heapreplace
#import numpy as np
#import networkx as nx
#from networkx.utils import UnionFind
#from numba import njit, b1, i1, i4, i8, f8
#from scipy.sparse import csr_matrix
#from scipy.sparse.csgraph import shortest_path, floyd_warshall, dijkstra, bellman_ford, johnson, NegativeCycleError
# numba例 @njit(i1(i4[:], i8[:, :]),cache=True) 引数i4配列、i8 2次元配列,戻り値i1
def input(): return sys.stdin.readline().rstrip()
def divceil(n, k): return 1+(n-1)//k  # n/kの切り上げを返す
def yn(hantei, yes='Yes', no='No'): print(yes if hantei else no)


def main():
    mod = 10**9+7
    mod2 = 998244353
    n, k, x, y = map(int, input().split())
    A = list(map(int, input().split()))
    dp = [[-1]*k for i in range(k)]
    dp[x % k][y % k] = 0
    dp[y % k][x % k] = 0
    max1 = [-1]*k
    max2 = [-1]*k
    max1[x % k] = 0
    max1[y % k] = 0
    max2[y % k] = 0
    max2[x % k] = 0
    for AA in A:
        A2 = AA % k
        for a in range(k):
            b = (0-A2-a) % k
            if dp[a][b] != -1:
                dp[a][b] += 1
                max1[a] = max(max1[a], dp[a][b])
                max2[b] = max(max2[b], dp[a][b])
            """
            if a != b and dp[b][a] != -1:
                dp[b][a] += 1
                max2[a] = max(max2[a], dp[b][a])
                max1[b] = max(max1[b], dp[b][a])
            """
        for c in range(k):
            dp[c][A2] = max(dp[c][A2], max2[c], max1[c])
            dp[A2][c] = max(dp[A2][c], max2[c], max1[c])
        for c in range(k):
            max1[c] = max(max1[c], dp[c][A2])
            max2[A2] = max(max2[A2], dp[c][A2])
            max2[c] = max(max2[c], dp[A2][c])
            max1[A2]=max(max1[A2], dp[A2][c])
        # print(dp,max1,max2)

    print(max(max(b) for b in dp))


if __name__ == '__main__':
    main()