## https://yukicoder.me/problems/no/1515

MIN_VALUE = -10 ** 18

def main():
    N, K, X, Y = map(int, input().split())
    A = list(map(int, input().split()))

    dp = [[MIN_VALUE] * K for _ in range(K)]
    update_dp = [[MIN_VALUE] * K for _ in range(K)]
    dp[X % K][Y % K] = 0
    dp[Y % K][X % K] = 0

    # max_valueの定義
    max_dp_x = [MIN_VALUE] * K
    max_dp_y = [MIN_VALUE] * K
    max_dp_x[X % K] = 0
    max_dp_x[Y % K] = 0
    max_dp_y[X % K] = 0
    max_dp_y[Y % K] = 0


    answer = 0
    for a in A:
        a_ = a % K

        # 結局Aを捨てるもの
        array = []
        for k_y in range(K):
            k_x_ = (- a_ - k_y) % K
            update_dp[k_x_][k_y] = dp[k_x_][k_y] + 1
            array.append((k_x_, k_y))
        
        for k_y in range(K):
            k_x_ = (- a_ - k_y) % K
            update_dp[a_][k_y] = max(update_dp[a_][k_y], dp[a_][k_y], dp[k_x_][k_y] + 1, max_dp_y[k_y])
            array.append((a_, k_y))
        
        for k_x in range(K):
            k_y_ = (- a_ - k_x) % K
            update_dp[k_x][a_] = max(update_dp[k_x][a_], dp[k_x][a_], dp[k_x][k_y_] + 1, max_dp_x[k_x])
            array.append((k_x, a_))

        #更新
        for x, y in array:
            if dp[x][y] < update_dp[x][y]:
                dp[x][y] = max(dp[x][y], update_dp[x][y])
                max_dp_x[x] = max(max_dp_x[x], dp[x][y])
                max_dp_y[y] = max(max_dp_y[y], dp[x][y])
                answer = max(answer, dp[x][y])

            update_dp[x][y] = MIN_VALUE

    print(answer)



if __name__ == "__main__":
    main()