#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;
  x %= k; y %= k;
  vector dp(k, vector(k, -INF));
  dp[x][y] = dp[y][x] = 0;
  vector<multiset<int>> mx(k);
  REP(i, k) REP(j, k) mx[i].emplace(dp[i][j]);
  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) {
      if (v > dp[x][y]) {
        mx[x].erase(mx[x].lower_bound(dp[x][y]));
        dp[x][y] = v;
        mx[x].emplace(v);
      }
    }
    vector<int> cur(k);
    REP(i, k) cur[i] = *mx[i].rbegin();
    REP(i, k) {
      if (cur[i] > dp[a][i]) {
        mx[a].erase(mx[a].lower_bound(dp[a][i]));
        dp[a][i] = cur[i];
        mx[a].emplace(cur[i]);
      }
      if (cur[i] > dp[i][a]) {
        mx[i].erase(mx[i].lower_bound(dp[i][a]));
        dp[i][a] = cur[i];
        mx[i].emplace(cur[i]);
      }
    }
  }
  int ans = 0;
  REP(i, k) chmax(ans, *max_element(ALL(dp[i])));
  cout << ans << '\n';
  return 0;
}