#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, k, x, y; cin >> n >> k >> x >> y;
  if (k == 1) {
    cout << n << '\n';
    return 0;
  }
  x %= k; y %= k;
  vector dp(k, vector(k, -INF));
  dp[x][y] = dp[y][x] = 0;
  vector<int> top1(k, 0), top2(k, 1);
  if (y == 1) {
    swap(top1[x], top2[x]);
  } else {
    top1[x] = y;
  }
  if (x == 1) {
    swap(top1[y], top2[y]);
  } else {
    top1[y] = x;
  }
  auto upd = [&](int x, int y, int v) -> void {
    if (dp[x][y] < v) {
      if (top2[x] == y) {
        if (v > dp[x][top1[x]]) swap(top1[x], top2[x]);
      } else if (top1[x] != y) {
        if (v > dp[x][top1[x]]) {
          top2[x] = top1[x];
          top1[x] = y;
        } else if (v > dp[x][top2[x]]) {
          top2[x] = y;
        }
      }
      dp[x][y] = v;
    }
  };
  while (n--) {
    int a; cin >> a; a %= k;
    vector<tuple<int, int, int>> update;
    int p = (k - a) % k;
    REP(i, k) update.emplace_back(i, (p - i + k) % k, dp[i][(p - i + k) % k] + 1);
    for (auto [x, y, v] : update) upd(x, y, v);
    vector<int> cur(k);
    REP(i, k) cur[i] = dp[i][top1[i]];
    REP(i, k) {
      if (cur[i] > dp[a][i]) upd(a, i, cur[i]);
      if (cur[i] > dp[i][a]) upd(i, a, cur[i]);
    }
  }
  int ans = 0;
  REP(i, k) chmax(ans, *max_element(ALL(dp[i])));
  cout << ans << '\n';
  return 0;
}