#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>
#include <atcoder/segtree>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

int op(int x, int y){
    return max(x, y);
}

int e(){
    return -1e9;
}

using Seg = atcoder::segtree<int, op, e>;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n, k, x, y; cin >> n >> k >> x >> y; x%=k; y%=k;
    vector<int> a(n);
    for(int i = 0; i < n; i++){
        cin >> a[i]; a[i]%=k;
    }
    vector<Seg> dp;
    for(int i = 0; i < k; i++) dp.push_back(Seg(k));
    dp[x].set(y, 0);
    dp[y].set(x, 0);
    for(int i = 0; i < n; i++){
        int rem = k-a[i];
        for(int x = 0; x < k; x++){
            int y = (rem+k-x)%k;
            dp[x].set(y, dp[x].get(y)+1);
        }
        vector<int> nx(k);
        for(int x = 0; x < k; x++){
            nx[x] = dp[x].all_prod();
        }
        for(int x = 0; x < k; x++){
            int cur = dp[a[i]].get(x);
            if(nx[x] > cur){
                dp[a[i]].set(x, nx[x]);
                dp[x].set(a[i], nx[x]);
            }
        }
    }
    int ans = 0;
    for(int x = 0; x < k; x++) chmax(ans, dp[x].all_prod());
    cout << ans << endl;
}